Mike C

IME, NADA is what a dealer can/will attempt to get for a car, while Kelly and Edmunds are more likely what an individual would get.

I don't think you can change the input since the 300 and 280 T5 have different first gear ratios, they have a different number of teeth. YOu would also have to change the cluster gear. Since the 300 is too long, you could disassemble the trans and have the input shaft machined to the 280 dimensions, but once again, unless that is the gear ratio you MUST have, might as well hold out for the 280 trans, or you are a machinist...

Nascar uses big block chevy size cam journals so they can get more lift and run a larger base tappet. They run roller cam bearings and they use mushroom solid tappets.

CKH 1972 CKH 307 Powerglide 1302 F A X/Apollo/Ventura 1973 CKH 350 m/t, 4 spd, NB2L48 1754 F A X /Chevelle/Monte 1974 CKH 350 m/t,3 & 4 spd, NB2 L48 160 4 F A X http://www.nastyz28.com/sbchevy/spcode2.html

I agree with what you say Luigi, but endurance type racing engines with .800 lift are pretty unusual, more of a dedicated quarter-miler thing. Completely inappropriate for a street engine that may see 10k miles a year. I think for 99% of SBC, what we discussed is quite accurate. But in your case, you are using the 1.6 rockers to solve a dimensional problem, once you move to roller bearing big block size cam journals you can once again grind a cam that will work with the 1.5 rockers. Or if you have a relocated cam journals. Switching to 15deg, 18deg, or SB2 heads obviously changes everything as well.

The V6 trans can be adapted with the appropriate bellhousing. It is not as strong as the V8 trans and has either a 3.27 or 3.50 first gear since not many people who bought V8 Camaros bought the manual trans. The V8 trans have a 2.95. They are not easy to find. Keep looking and eventually one will turn up. WHen you need something specific, you can wait and get it for what you want to pay, or get it right now and pay whatever who has it wants. Another option to consider is getting an adapter bellhousing/scattershield (McLeod and Lakewood both make one of these.)and using the Ford T5 which is MUCH more common. I would even consider buying one new, or the Tremec for a Ford. The adapter bellhousing lets you use the Ford trans and comes with a special pilot bushing.

CKH is the 3 letter code that says what application the engine was originally installed in. My book is out in the shop, so I can't say what wpecific application was. The 010 on your motor shows it is a 1% tin/ 1% nickel block. If there were two numbers, 010 and a 020, shows a 1% tin and 2% nickel block. The 3970010 was available either way and in two or four bolt configuration.

The front of the cylinder block deck, on the passengers side, you will find a serial number and a 3 digit code that IDs the motor (behind the alternator if it is still attached). Post the code and I'm sure somebody will verify. If the motor has ever been decked, or possible even if it was surfaced, this number may be gone. You can use the casting number to verify displacement (above the bellhousing mounting area on rear of block.) and casting dates to verify year, but not specific application.

For a max engine speed of 6500 rpm, check out the Comp 280AR Magnum solid lifter cam. I have one of these in my 355. It has probably 15k miles on it or so with no durability issues. It pushes my 3500# car to 12.7's at 110 mph ( 2.0 short time ), idles at 800 rpm at 12". Pulls hard from 2500-6500 rpm. 280/280 advertised, 236/236 @ .050 and .550 gross lift, I lash intake and exhaust .020, but next lash I think I'm going to tighten the intake up to .018.

With my built 327 I think I had 67 in the primaries. With a stock 350 I think you can jet it down even further, say 65, and add the stiffest secondary spring you can get. 4.10, 24" tires, and 5.7liter engine just isn't going to get very good mileage... Actually, if you keep engine speed down (cruise the slow roads) and keep your foot out of it, no reason you shouldn't get 14-16 mpg. One thing about 4.10 is the engine doesn't work very hard to get up to speed!

I was just re-reading your post about that 377 again. I had a Comp "NOT FOR STREET USE" cam in my 355 back in '87. It was in a '68 Camaro SS that my brother bought from me. It was 300/300 advertised 265/265 @ .050 and .540 lift also 106 LSA. It was a monster. I had never ridden in a SERIOUSLY cammed car before, and man, was it a blast! I had the 4 speed I'm running now with 4.56 gears in the back. You'd let out the clutch about 1500 rpm and stand on it while it just cruised away, until about 3500 RPM when your neck snapped back, the front lifted up and the tires let loose! What a gas! From 3500 it flashed to 7500 almost before you could push the clutch in and yank the lever. It would flash 7800 or so on the shift, then blow the tires off again! I never ran the car, but I figured mid 11's would not have been a problem with the big gears and lightened chassis. I run the same motor with the baby roller cam now, and it's smooth and docile 425 hp or so, but I figure the monster cam made at least 475 hp. Big cam=big fun if you don't have to worry about driveability.

The myth that a vac secondary only uses as much fuel as the engine needs is mostly still a myth. The flow of fuel through the primary venturi reaches a certain point, it creates enough vacuum signal to the secondaries that they open. Fuel metering is still controlled by jetting. What kind of motor do you have? IS it a 383 as your name suggests or a lame stocker? Assuming lame stocker 350, a 750 vac is WAY overjetted in the primary and a 350 ci motor will still be able to injest plenty of fuel through the primaries to open the secondaries. If you have a 4160 with a plate in the rear, the secondary jetting is fixed. Either you are running way rich on the primaries or your vac secondary spring is too light and they are opening quite a bit and a low throttle settings is another scenario. You can improve your economy to some degree by working with ignition timing and carb jetting. In that sense the 600 is much more appropriate for your combination. Honestly, 4.11 gears is just too much for a stock engine. Your best bet IMO would be switching to a 3.54 geared rear axle. Now, if you have a built 383 as your name suggests, you have 10% more displacement and are turning a ridiculous RPM at cruising speeds if you have a 3 speed auto and the 4.10. A better solution would be a TH700 and the 3.54 gears along with a correctly tuned and adjusted 750.

That must have been one of the later episodes, because his original wheels were a Sunbeam Tiger another of the original "Hybrids."

I don't think it will work. I think the V6 trans has a longer input shaft. If you want to measure yours and post, I'll do same with my 280ZX T5 and we can compare.

Interesting. It would not surprise me if different manufactures, and even different modesl, designed their rockers for longer valve lengths. This would explain why different pushrods were required even within same ratio. Lots of roller cam springs are designed for .100 longer valves to accomodate the amount of lift, and race rockers you would think were designed for a similar setup. I have stock length valves in my motor with the 11752 but need +.100 pushrods to restore correct geometry. Believe it or not, the Crower motor was based on an old ZZ4 and used the GM L98 heads. It averaged 475.9 lb/ft and 409.7 hp (I forget the range, 2500-5500 or so?) with peak of 544.6 hp and 518.8 lb/ft using a 4.00" bore and 3.625 stroke. One of the other mags did a rocker swap dyno tests last month and found the most power with 1.5 rockers on the exhaust and 1.6 on the intake. SB Ford's really respond well to split pattern cams that are heavy on the exhuast, but they have TINY restrictive exhaust ports and short well-flowing intakes. Because of the averaging in low rpms used to determine qualifiers, lots of people went to longer strokes. I REALLY like the 377 for big peak power. Amazing how much going to the 4.125 or 4.155" bore helps to further unshroud the intake valve. Notice also that the serious small block race heads continue to increase intake valve size to 2.1" but seldom do you see more than 1.65 exhaust valves which also implies to me that these motors need further help on the intake side. Intake valves are often shifted off center to further improve flow and allow those big valves. I guess if you tuned the exhuast to take advantage of the added duration in order to maximize scavenging and therefore cylinder filling (which translates into better flowing intake?), the split duration cam might really pay off. I think on a vehicle that has to deal with a full length exhaust system that exits the rear and has to conform to the floor cannot take advantage of that. The more I think about it, the more there seems to be discrepancies in what the cylinder head designers and cam designers are doing. I wonder if the cam companies design there "street" performance cams around a set of stock cylinder head castings with only 65-70% i/e flow?

Not chrome, but the best mirror that I have found for an early Z is the 70-81 Camaro/Firebird bullet mirror. They are the same shape as the Z and mount to the door. Have to drill three holes on drivers side and two or three on pass. depending. All of the drivers mirrors are remote, cable adjusted, but only some of the passenger mirrors. You can even mount the remote adjuster into the doorpanel using the GM flat chrome bracket. Trick. I have them on my current and car and my last 240 as well. Note that GM used the same mirror housing on other cars, but the stalks are different. The F body stalk fits the best on the Z.

Have you been following the Engine Builder Challenge in PHR magazine? Did you see the motor entered by Crower? They wound up keeping the 1.3 ratio "break-in" rockers on the exhaust side becasue it didn't need anything more. Their engine was running a flat-tappet mechanical cam. (This is a very interseting ongoing segment with some excellent ideas for high-powered street engines. If you want to make big power and drive it, throw out those hydraulic lifters!) If a motor makes more power with a split duration cam, it is my opinion (and we all know about those...) that something else is out of whack relative to the cam. NA SBC do not need added exhaust flow relative to intake, unless there may be some sort of restricted exhaust PAST the cylinder head. Like everything else, in dyno-matched and tuned combinations, small to large gains can be had, so be wary of my blanket statement. But seat of the pants, or street-car level power, will not be affected significantly if the right size cam is chosen for the rest of the combination. In reading up on LS1 rockers, you should use a cam specifically designed for whatever ratio rocker you plan on running. Using the 1.8 rockers on a cam designed for the 1.7s will result in broken valve springs because the effective ramp speed gets out of the designed range. This further illustrates to me that 1.6 rockers should be either planned for or not, but not used unless the package was specifically engineered for that ratio. Or it is a pretty small, mild camshaft. Cylinder head mods as noted above are the other reason. I have a friend running a year old set of Harland Sharps. They switched vendors for pushrod cups, and a bunch had machining troubles. They replaced his no charge. No troubles since then. If you run them, and I think they are a good product, just carefully inspect the pushrod cup to make sure it is polished and no machining marks are evident, other than that they should be good for mild to wild motors. I have had excellent luck with the Crane Gold Race rockers. I have the 11752's on my 355. They are 7/16" stud and designed to clear 1.630 springs. The cheaper Gold rockers hit the retainers even though my springs are only 1.44. Highly irritating.

Yea, I can't BELIEVE Nissan stole SAABs design for the first gen 300ZX

try www.reiderracing.com otherwise, bearings are reasonably standard and can be acquired at the auto parts store or a bearing supplier. There is also the dealer as well.

Like Big Phil said, 8" rim is measured between the mounting rings. 8" rim is really 9" wide if you measure outside to outside so the center is 4.5" from the outside of the inner rim where backspacing is measured. Which extrapolates if you notice that the zero offset 7" wheel has 4" backspacing.

I ALWAYS preach against 1.6 rockers as I see them as a crutch. MOST people with mild street cars considering 1.6 rockers have GM cylinder heads without screw in studs. In order to safely use 1.6 rockers in non self-aligning rocker motors, the heads should be removed and the pushrod slot elongated OR drilled out and screw in studs and guideplates installed. All of a sudden your "cheap" swap is a PITA requireing a top end gasket set AND pulling the intake and almost all the other stuff trying to avoid with a cam swap. Or you bend all the push rods and wasted $200+ and have to do it all over. So I agree with Grumpy, tuning aid on a very high-performance engine, or a band-aid for lazy mechanics. Even cheap rockers are 50% more expensive than the Energizer cam kits. I still prefer single pattern cams over dual pattern cams in SBC with any sort of decent head, and dyno tests seem to bear me out. SBC have problems in the intake, not the reasonably short, well flowing exhaust. I do like the comp magnum roller tip rockers, not for lift/power, but for longevity. It is my experience that they reduce side-loading of the valve improving guide life, and max longevity is usually a priority to me.

The 278 should "lope" nicely about 800 RPM. At 600 RPM it will REALLY lope! Stay conservative as torque is what really zips you along in a streetcar. For 8.5-9:1 compression and the 200 cfm or so your heads will flow, the 278 is plenty big a cam. I have the 266 in my Jimmy with 9.5:1 and closed chamber heads (vs. your open chambers ~ 20 hp.) and I guarantee it would run faster now than it did in my Camaro with the crappy 284 cam. The 266 is pretty much cooked by 4500 rpm however, it would make for as sweet driving manual trans V8 car IMO, but RPM is too much fun in a light car, and the 278 should be good to near 6k depending on ability of heads to flow. A few hours with the grinder pocket porting the heads and making sure you get a good 3 angle valve job with a 30 deg backcut on the valves should really help, at least to the tune of 25 hp. I think this can be done for $1000, including the kit and machine work, but excluding peripherals (intake, carb, ignition, exhaust, etc.)

Zero offset on an 8" wheel IS 4.5" On a 7" wheel it is 4". Because of the extra width, however, you may have to go 5" and run coilovers for clearance on the outside of the tire in front AND rear. IME, 7" wheel is all that will fit using stock suspension and maintaing a reasonable tire height. If you run a really short height (which won't happen with a 17" rim, you can get away with it.

Another option is a first gen Eclipse, Talon seat. Even easier than the Miata seat, it requires ZERO mods to the floor pan. Chop the "foot" off the rear of the Eclipse slider and weld a stud to the slider that lines up with the rear hole in the Z. The front hole bolts directly to the Z's hole using the Eclipse hardware. They are even the same shape as the Z seats for the most part. This will probably not work for you if you are over 6" tall, but if you are 5'6" you'll actually be able to rest your arm on the window. I'm right at 6', and I don't think I can ever do a rollbar since my head is right ther, but they fit well, are really comfortable and reasonably priced. They all have adjustable lumbar, but the sport seats have adjustable thigh support as well. The adjustments are all mechanical and require no mods to car or any wiring or control installations. Here are a couple of pics, first with my Talon sport seats and then with Eclipse standard seats. (FWIW, the Talon seats are FS, $100.) My server is down, will post pics when it comes up...

Ah, Tim, Great minds think alike...