Michael

What makes the V8 swap complicated isn't the swap itself, but the various improvements, hop-ups and "while I'm at it" modifications. To begin with, most people have a Z with a significant amount of rust. I'd say that >50% of the swaps which get mired into multi-year marathons ended up that way because of body work. Second, in an effort to build a competative street/strip car - rather than a mere street car for personal enjoyment and non-competative recreation - many people try to push the technology envelope. And third, there are indeed flavors of the V8 swap, such as using fuel injection or an unconventional engine, which turn the project from modest to very complex. If this is your first "hot rod"-type vehicle, the best strategy - and I'm speaking from 20/20 hindsight - is to follow essentially what JTR recommends; buy a mid-priced 240/260/280, buy a 1970's full-sized sedan with a 350 and an automatic, and mate the drivetrain of the latter with the chassis of the former. Don't worry about the rear end for now. And don't worry about the 300 hp. In the long run, it will be cheaper to install a 180 hp smog motor, get the car running, and later swap to a hot small block.

If you have a non-overdrive transmission with a torquey engine, a 3.15 (or numerically smaller) gearset is very useful. For example, in my application (454 BBC with 6000rpm redline, Doug Nash 5-speed with 1:1 5th gear, 3.54 R200, 24â€-tall tires) gives a max allowable speed of 121 mph. With the right tires and suspension setup, that will hopefully not be too far from my expected 1/4-mile top speed. So no problems there. But, cruising at 70 mph gives 3470 rpm – and that’s a little too high for comfort. Even a 3.15 is numerically too high, considering that first gear is 3.27:1, and it’s a big block. Something like a 2.7 rear would be even better.

Gen I SBC and Mark IV BBC have the same engine mounts and the same bellhousing bolt pattern. A BBC longblock will fit in the 240-280Z without any “cuttingâ€, but be aware of complications in fitting the exhaust tract, in how far the oil pan hangs down (especially if you’re using the 9â€-deep truck oil pan) and how far the air cleaner sticks out (especially with a Performer RPM-type manifold). The blown 454 mentioned above has, I believe, changed hands, and now sports a SBC. There’s still a handful of BBC Z’s on this site. Mine has some sheet-metal mods, including a setback firewall location and some chassis reinforcement, but the rear end is stock (R200). Other BBC Z’s are back-halved. Bottom line – yes, it can be done, and no, the weight/balance issue isn’t necessarily a showstopper, but there definitely are complications. It is NOT as simple as the JTR SBC swap. And while the JTR-type SBC setback plates might work, it would be better to mount the motor to the frame rails (with suitable reinforcement).

I visited the Monrovia p-n-p (east of LA) the other week - my first visit to a self-serve junkyard in about two years. There was only one Z in the entire yard (a 280Z). You folks in California are lucky to have p-n-p junkyards. Here in Ohio they're extinct. That said, prices for used parts are definitely going up. This is strange, considering that prices for new or remanufactured parts at Autozone-type stores seem to be stagnating, or even declining. Would this be a consequence of Chinese manufacturing?

Considering that the differential failed while the halfshafts and stub axles did not, it's not inconceivable that your differential was damaged to begin with, and that one full-throttle clutch dump was enough to finish it off. A stock R200 in 3.54 or 3.7 ratio goes for about $75, and at that price, it's worth reinstalling a stocker, subjecting it to the same "abuse", and seeing if the failure repeats itself. The proponderance of stories about rear-end failures strongly suggest that a R200 should be OK for your application. That said, there's nothing wrong with a solid rear axle, especially if the car is a dedicated dragster. But that's major $$$ and requires considerable engineering.

If you’re comfortable with 350 hp I’d stick with the 236 heads; they should be adequate at this level. 400 hp should be possible with a little portwork. With no valve job (at all), my home-ported 236 heads reached something like 260 cfm at 0.500†at the local flow bench; this is about 25 cfm above stock. If one believes the rules of thumb, even the stock 235 cfm is enough to support 350 hp, easily. For the 236 heads I would recommend straight-milling them a bit to increase static compression – if you don’t plan to rebuild the short-block. If you do rebuild the short-block, get mild-dome hypereutectic pistons, such as what I bought (“Sealed Powerâ€). BTW most aftermarket BBC pistons already have their skirts coated. For the 236 heads, 0.007†of straight-milling gives approximately 1cc of combustion chamber volume reduction. For your application you only need to remove about 5 cc – but check piston to valve clearance. Chevy High Performance magazine has a web page with a database of most SBC and BBC head flow numbers. And if you search in this forum under “DCRâ€, several of Grumpy’s posts on dynamic compression ratio calculation should pop out. There are various sites where you can download a DCR calculation program – not to say that it’s difficult to write one yourself. What’s more difficult is reaching a consensus on what DCR value is OK for what octane value, and various other variables. It depends on combustion chamber shape, piston dome shape, quench, cylinder head material, alignment of the planets and color of the pavement. Well, not entirely, but sometimes it feels that way.

Something similar, though not quite as drastic, happened to my 280Z. It’s been sitting in my garage for about 5 years, sometimes with the windows open, sometimes closed. The mold is especially attracted to the vinyl of the door skins – but hardly at all to the headliner or seats. This is in Southwest Ohio, and the garage is basically in the middle of a forest, so the environment is quite humid.

I had a MK III Supra Turbo 5-speed (1987); bought it in 1995, sold in 2000; my first "sports car". Since I'm a low-rpm guy, this car was nothing but frustration. When I lived in Los Angeles, I once went to Pomona for test-and-tune. After one of the best launches of my life, I reached... 86 mph @15.8. True, by then the head gasket was not far from failure (again!) and the turbo only spooled to about 5 psi. Before the Supra, I had a Corona (1970's RWD precursor to the Camry) and 1983 Celica. The Supra turned me away from Toyota - until I ended up with a early 1990's Corolla (reached 225K miles before the rust killed it). Bottom line - with the proverbial right mods and right driver, Supras can exhibit impressive performance, but a stock Supra with a mediocre driver isn't particularly impressive.

If this is a 1979 then it’s a Mark IV 454 with flat-tappet hydraulic cam. The 236 heads have 225cc intake ports and 119-122cc combustion chambers (depending on which reference source you believe). If your intended application is for the truck, then the peanut-port heads are entirely adequate. Port-work to consider would be partial port-patching (don’t go all the way – see below!) to an Edelbrock Performer intake, clean-up of the inner-radius in the exhaust ports (exhaust ports on 236 heads have a very sharp inner-radius corner!) and bowl-blending on all the ports, as often one finds something like 0.100†“steps†in the port casting. And as the others already mentioned, the pushrod-through-the-rocker situation is probably a symptom of a wiped cam; which means a complete teardown. If this engine is intended for a Z (ambitious, but not impossible) then you’re looking at $2000 for aftermarket heads and >$1000 for a suitable valvetrain (good lifters alone are $500!). Yes, there are cheaper alternatives, but they negate the performance advantages of the BBC. I started with a 454 from a 1978 Suburban – basically, the exact same engine as what you have. I did the above-mentioned port work on my 236 heads. When the machine shop pressed in new valve seats, the heads cracked; evidently, I removed too much material when trying to port-match with my Edelbrock Performer RPM intake. The port work took several months, with 1-2 hours a day, several days a week. This is with a Sears 1/4"-collet electric die grinder (basically a giant Dremel) with a range of grindstones, including a $30 carbide cutter. Even at 25,000 rpm with the carbide cutter, cast iron takes a LOT of time to remove – and the shavings are nasty! With glasses and a mask I still ended up with dust in my eyes and nostrils. So all that port work was for naught. Eventually I mustered the gumption to buy aluminum heads. In a truck the cast-iron Pro Topline heads would be an interesting option, but in a Z I just couldn’t justify not using aluminum heads, whatever the cost. For some time I’ve been waiting for AFR to bring their oval-port heads to market. But 2 years is long enough to wait! Brodix recently came out with their “Race Rite†oval port (271cc) heads – and that’s what I currently have on order. For my build, I used the block, crank, rods and damper. In hindsight, I should have gotten aftermarket crank and rods – or at least the rods. Because the short-block was built with 236 heads originally in mind, I bought 10.5cc-dome pistons, which give around 9:1 SCR with the 236 heads. The original plan was to use a hydraulic roller cam. The current plan is to use a healthy mechanical roller with the Brodix heads. Brodix can mill the combustion chambers down to 110cc, which gives (if I recall correctly) something like 9.6:1 SCR with a 0.039†head gasket. If you follow Grumpy’s posts, you’ll notice that this is quite low for a big block, let alone one with a mechanical roller. But the duration is pretty small and I intend to install the cam with considerable advance, giving a DCR in the 7.8:1 range (or higher). Anyway, my point is: keep it simple if your application is a truck, but if you’re going for a BBC Z, you’re looking at another $4K-5K to build the engine “rightâ€. That should give just shy of 500 hp and around 550 ft-lb torque

Dave88ss - another Dayton member - welcome! I think that makes about 3 of us. One of the few advantages of living in the Midwest is that land is cheap, and there's plenty of space for building large garages. I live in the boonies, and though home ownership has been an almost unmitigated disaster, the 24' x 40' garage is convenient.

Now your sig says that you have a Toyota Corona - man, that really brings back the memories! My parents had a '74, then a '76, and finally a '78. The '74 was an automatic - we trashed it when the transmission died. The other two succombed to rust or ill use. What sort of engine will you swap into these? Please don't make it a turbo.

Understood about the piston-speed constraint. But what do you think of the following train of thought: going from a 4.375 to a 4.5 stroke (for example) is only about a 2.9% increase in piston speed and displacement. If the engine maintains the same peak volumetric efficiency, peak torque should rise by the same 2.9%. And if the rpm for peak V.E. goes down by 2.9%, peak hp stays constant. However, for the same compression ratio the 0.125†extra stroke buys a 2.5cc reduction in piston dome (if I recall correctly the specs of your heads) to get the same compression as with the smaller stroke– and conceivably, with the smaller dome the result is a slightly lighter piston with slightly better flame-front propagation, hence better combustion efficiency. So, because peak hp hasn’t budged, the benefits in a racing engine are questionable – but in a street engine, especially in a relatively heavy car like the Corvette, the trade of extra stroke at the expense of reduction in peak rpm might make sense. Do you have a broad choice of gears for that Dana 44 (or whatever differential the Corvette uses)? BTW I’ve heard elsewhere that copper head gaskets are tough to seal for an aluminum head/cast-iron block application (yes, I know that your application is an aluminum block). This seems counterintuitive, and contradicts some discussions on this site – including, if I recall correctly, your posts. What’s your opinion on copper head gaskets in the 0.040â€-thickness range?

I second jmortensen’s comment. Life has improved IMMEASURABLY after getting married (at the tender age of 30). I even have more time to work on my Z, since there’s some one to share the housework! What ties you down, saps your energy and wastes your time isn’t a spouse – it’s the children. Avoid them as long as possible – or, ideally, forever. “Playing the field†only works if you’re a player by nature. Are you suave, resourceful, blessed with an attractive appearance? When I was 21 all that I did was study and save money. Between the 6 hours of homework everyday and the cystic acne, dating wasn’t an option. Regarding your vehicular dilemma, sell BOTH the Grand-Am and the Z. Your Z is a 1979 ZX, and please don’t take this as an insult, but it’s not a classic, and is unlikely to appreciate in value. So sell both of those cars and get an econobox beater that’s reliable, cheap to insure and easy on gasoline. As for figuring out what you want to do in life – well, that can only be accomplished in hindsight, and even then it's not clear! I know people in their 70’s – that’s right, in their 70’s – who are wrapping-up 45-year-long careers in engineering, and they still don’t know what they want to do, and they still have regrets over having gone into aerospace engineering during the Eisenhower administration!

Before you swap in that 7M-GTE, weigh it. You might be surprised. Years ago I had a MkIII Supra, with the 7M-GTE; used to frequent the Supra boards. There were several 7M-GTE swaps into the MkII (1983-1986) chassis. And there was a SBC swap too – that one was my favorite.

Yes, this topic has been discussed over and over again, but as the FI technology keeps advancing and LS1 engines become ever more popular, it’s worth revisiting the discussion. That said, I’m still going with a simple 4-barrel vacuum-secondary Holley. Why? Because whereas I fancy myself to be reasonably competent with automotive engineering and the occasional custom fabrication, my skills in basic auto mechanics are mediocre at best, especially in automotive electronics. For a daily-driver FI is the ultimate solution, but for a very occasional car (and mostly a wannabe race car) carbs are a satisfactory alternative. If I can’t tune the carb, I can find a local mechanic who can. That won’t work for a custom FI system.

The BBC conversion is a handful. I don’t want to insult the people who believe that it doesn’t require anything “radicalâ€, but suffice it to say that I couldn’t disagree more strongly! Weight and balance issues can be overcome, but they are not trivial. There is no analog to the JTR kit, though the Mark IV BBC and the Gen I SBC have the same mounting bolt pattern, and the same transmission bellhousing pattern. There are (or were ) some 5 or 6 big block Chevy Datsuns on this board, but to my knowledge all are either backhalved, tube-chassis, altered-firewall or some combination of the above. Mine retains the stock suspension and nominally the stock front end, but the firewall is relocated aft for better balance and more clearance, and there are a few reinforcement tubes here and there. The BBC swap is worthwhile if you’re a BBC specialist and would like to carry that knowledge over to the Z world. Otherwise the safer bet is on a stroker SBC. But like 5foot2 said, mock-up the engine installation and gauge for yourself whether the fit is acceptable or not, whether the headers hit the frame rails or not, whether the steering shaft clears or not, whether the crank pulley hits the steering rack, and so forth. Then worry about engine mounts – you’re almost guaranteed to have to mount off the frame rails, not off the steering crossmember (as most SBC’s mount). And then proceed to considerations of structural reinforcement. It isn’t strictly necessary to radically alter the engine compartment, for example by relocating the firewall aft, but it makes sense from an overall balanced-car (literally and figuratively) point of view. Don’t hesitate to post specific questions if you have them. I don’t want to come across as excessively negative – but it’s better to forego a risky project than to go knee-deep and then capitulate.

Scottie, If you could get me that phone number, it would be a huge help - thanks!

Oops, disregard question #2 - they ARE the same lifters.

What I meant to say was that this is not a gimmicky attempt at variable valve timing; it just has 9 keyways instead of the more usual 3, and the gears are billet steel. Otherwise it’s just a regular “true roller†timing chain set. My only frustration (well, at least in this particular context) is that I’ve never heard of SA, and I’m reluctant to purchase a brand with no reputation.

Questions for you, Grumpy – 1. To what extent should we trust those DD2000 numbers? 1951 ft-lbs at 2000 rpm??? Running a “junior version†of your engine (461, Brodix Race-Rite oval-port heads, 0.640†mechanical roller, dual-plane, 750 cfm, also 6000-rpm limit, but no nitrous) on DD2000 ad nauseam I also get remarkably good numbers – like 596 ft-lb at 4000 rpm, 559 hp at 5000 rpm. In my application, by the way, DD2000 predicts a drop of almost 150 ft-lb in going from 5000 to 5500 rpm. 2. Are those lifters similar to the Isky Red-zones? 3. I understand the quoted bore limitations with that block, but why not a larger stroke? 4. Any nitrous-specific considerations for the cam, such as greater intake duration than one might have chosen otherwise? 5. Would the deck have to be O-ringed? 6. What sort of valve spring pressures would be needed? Would you need a shaft rocker system? 7. At this power level, are there any symmetric-port heads available with “smallâ€-enough (as opposed to pro-stock) intake ports?

For my 454 BBC an engine builder recommended a "SA adjustable billet timing set". Has anyone ever heard of SA? They're not in the Summit or Jegs catalogs. It's supposed to be a relatively high-end timing chain, with 9 keyways.

Let me add to the chorus of congratulations!!! It takes considerable wisdom to find the right balance between doing work by oneself and farming-out portions to others. Done right, the reward is a reliable car that's ready in a small fraction of the time. I'd love to see this thing on my next visit to the D.C. area (should be in late August/early September).

In a matter of hours this thread will be filled with posts, some dignified and some less so, enjoining you to search more thoroughly, as all of your questions have been answered multiple times before. But briefly, the R200 should be OK for your application; the weak link is the half shafts and their U-joints, for which there are relatively straightforward solutions. The 5x4.5" swap has also been done n-number of times before, and there are several members (vendors) on this site who sell stub axles and related components to enable the swap. Wheel/tire choices depend on whether you do the coilover swap, what ride height the car will achieve, the tire diameter and other specs, and your choice in aesthetics. So, the point is that the rear drivetrain and suspension is the least of your problems. First worry about doing the actual swap and achieving your desired 500 hp. Then worry about traction, halfshaft breakage and so forth.

Douglas - Point taken. I'm trying to be realistic about my results. Had a stock or stock-like hood been usable, I would not have done this. But, with the firewall relocation and other mods, I need a hood whose front lip begins somewhat aft of where the stock 280Z radiator "frame" is located, and which ends at the windshield, and which has about a 1/2" bulge to accommodate the air cleaner (any higher and my forward line of sight would suffer, as I'm short but I have to sit way back (Kirkey sheet-metal sit up against the rear wheel well). So far I have a spider web of thin wood planks, forming a structure akin to balsa wood model airplanes of the 1930's. I used a similar approach to built a sort of stubby G-nose, which is bolted where the original hood hinges bolt. There the finish was mediocre, but acceptable for my tastes. The foam which you mentioned - what is it's brand name, and what sort of retailers (home improvement stores? boat stores?) would carry it? Would it dissolve if covered with polyester resin? I prefer polyester resin to 2-part epoxy (very tolerant to incorrect mixture ratios of resin/hardener, very long working time), but the polyester resin has a solvent which eats away white insulation-type foam.

No hope of fitting these without spacers if using the stock springs (no coilovers), is there?