Mike C

I think you are spot on about the restriction. Oil cooler lines are typically at least double the diameter of the auto trans lines cooler lines. I think you can get a rad with a heat exchanger built in it that will have sufficient flow to function as an oil cooler, but if memory serves they cost as much as a good used Datsun...

Probably simple carb adjustment. I am assuming you have a Holley carb here...I would start by checking the float levels. If the front is too low or the rear too high this can happen. In the front the fuel moves away from the metering block and their is no gas for the idle circuit and the engine stalls. If the rear is too high then fuel can come out of the vent and effectively flood the engine since the throttle blades are closed there is very little air to offset all of the added fuel.

You will need to get a custom set of pistons, but if memory serves, the "little" LT1 crank is a 3" stroke. You can get a set of SCAT rods brand new for $219 and with bushied 6" rods for $269. A set of flat top 3" stroke pistons will eat you up, however at around $500 (which seems like a smokin' deal compared to 6 L6 forged pistons at $900!) Coupled with the 350 LT1 block standard bore would give you a 302. GM did this in a 30th anniversary 67 Z/28 they built back in 1997. Torque Vendors gives you some good advice. I like the idea of the high winding 302 vs. the 383 torque. While making less overall power, a 7000+ rpm is an awesome experience. Add your aluminum heads and an aftermarket LT1 camshaft. If you are using all of the FI parts for the little motor, you need to investigate and find out if the intake is the same or has smaller ports. You will have to increase the injector size as well, but the stock 350 injectors should work well in a high winding 300" motor.

The 77 should have 3.54 gears. Your motor with the cam and stuff might be 275 hp. The cam is all wrong for those heads, IMO as I stated in the other post. The performer and 650 Holley are both also good for a motor up to around 300hp.

Are your vacuum numbers just at the MAP sensor? I think you have a vacuum leak, however. The 22" at part throttle is quite believable, but the 8-10 at idle is wrong. The pressure reading at the MAP should equal the engine vac at all rpms. idle should be close to 18" if not higher, part throttle can vary widely between 5 and 25 depending and WOT should be zero.

Don't know about the ZX. You can use the regular cover with no problems and will HAVE to unless you want to do major reconstruction of the rear diff mount.

Unless you modify the rear diff mount, the finned cover has to come off anyhow.

See above. 10" diameter 280zx rotor and 10.8" diameter stock Z rotor. With the 240-260-280 mounting point of the ZX caliper it would hardly cover 2/3 of the pad surface area AND the smaller diameter would reduce the amount of leverage the caliper could put on the rotor. The 300zx rotor is 11" so you can slightly reduce the OD and use the stock mounting "ears" on the Z series struts after drilling the threads out.

Another advantage to the side tank radiators is they expose the cap to less than the max pressure of the cooling system. (since the cap is on the suction side, unlike the Datsun where it is on the pressure side with the top tank.) So a 15psi cap on a side tank should be more pressure capability than a 15psi cap on a top tank.

All manual trans cars from 75 should have the r200. And all of the 2+2 I believe. Nothing hard about building an r200, either.

Your limiting factor is your wheels. If you really want the maximum diameter tire, you will have to mod your strut as noted above, and buy wheels that will work with the tire you want. IME, more backspacing on the Z, front and rear, make for a better driving car. Going to larger diameter rims reduces the sidewall height which in turn reduces sidewall flex giving you more control (ability to run tighter clearances) as well. This also gives you more clearance at the strut since the tube is at an angle and the wheel lip is higher up the angled tube, you can run more backspacing. Scotties mod and 17" wheels. You've been looking for an excuse anyhow, right?

Also, the Z's brakes are 10.8" in diameter and the 280zx are only 10" in diameter. The early 4 lug 300zx is 11" and must be slightly reduced and can be used with 280ZX calipers. As noted, check out Terry's most excellent article.

L-98 (Camaro/Firebird/'vette) 245-255hp. Pickup/Caprice ~200hp. I'd just buy some TRW or SpeedPro (Sealed Power) lifters for about $2 each. Use LOTS of cam break in lube. If you have stock cylinder heads, IMO the 280 cam is too big. You should get something smaller with around 210-220 degrees duration at .050 instead of the 230 typical of most 280 cams. Crane Energizer with lifters ~$100. 88 should have the more straight up and down intake bolt pattern that showed up in '87 (unless Al heads)

I have a '78 r200 in my '72. I only changed the diff and the mustache bar. Rear mount was same and stock half shafts were fine. I have seen a different style setup on r180's, but only on an older car than '72. All of the pinion yokes should be same until ZX diffs.

If a 12 point socket won't work (and from the star description, sounds like it won't) then it is probably a torx nut requiring a torx socket. You shouldn't have trouble finding a set at wherever you get tools/parts.

Are they just too tight? Typically when a rod is built, it is surfaced to make the hole undersized, the bolts are torqued, and then honed to correct size. Clamp the big end of the rod in a vise with a block of wood on either side of it, then use a socket to take the nut off. If the rods have cap dowels, you may have to tap the cap to get it off. Use a brass hammer VERY JUDICIOUSLY to loosen the cap.

Regardless of what you do for a crank, you should balance the complete rotating assembly with the new crank. If it is just a "stock" motor, I guess it wouldn't have to be done, but if that is the case, just get another one piece rear seal crank and just put it back together. I would assume that the part of the crank inside the block is balanced approximately same as the older cranks, but the end where the flywheel bolts on is different and requires a counter balanced flywheel, which means in addition to the seal conversion you will have to buy one of those if you don't have it. How did the thrust surface get damaged? Pounding on a balancer or a ballooned converter?

I'm glad your OK, but nobody else saw him, what makes you think you will? Having a gun doesn't make you any more bullet-proof than drinking Tequila Pumping gas and bang your dead... I think I'd mosey on down to the neighborhood gun shop and get me a Kevlar vest, just in case. Just 'cause you're paranoid... ya' know? Althoug at least one was shot in the head. I hope the SOB suffers horribly for an extremely long time...

Bill, you should definitely get your points situation under control. Ignition timing has to be spot on before you can spend any time at all on other woes. I know when we were monkeying with it before, that point set you had was WAY whacked. They work quite well if set correctly. You can get a set of Blue Streak points for about $8 or a set of Accels for $14 or so. The 9.8:1 331 in my Jimmy had an LT-1 high rise with a 70 Z/28 780 Holley and a Cam Dynamics (now Crane Energizer) 284/284 .480 cam. I ran the truck 2" rams horns and a single 2" exhaust. With NO overheating problems. (It also had a stock points distributor because of firewall clearance issues.) I was broke and in college and it was the old motor from my Camaro that was in the garage when the originally one in the Jimmy expired. Admittedly, adding a set of headers and 2 1/4" exhaust was worth probably 80 horsepower. I find it hard to believe it's the exhaust, but fuel mixture (unlikely with the 750 but you never know...) and ignition timing are most likely the suspects. I'll still put the dwell meter on it if you'll get a set of points.

I used the Pertronix in my last car for over 7 years on the 240 distributor. I cooked the Pertronix I put in my current car doing a compression check. Crane also makes a conversion they call the XR7000 that comes with a hall effect pickup and their box, but you can use the MSD instead. Also, Mallory has a Unilite conversion for the points distributor. Mallory also makes a magnetic pickup distributor that uses their tiny cap and their distributors are short as well which makes for more clearance at the firewall. All of those options are from the $60 range for the Pertronix up to $200 or so for the Mallory distributor.

If it doesn't have the internal clips (half moon on the inner side of the cap),out of the side of the driveshaft you will see some little plastic nubs. GM used theis molten plastic injection to hold the u-joint in. You need to melt the plastic out, then you can replace the u-joints with autoparts store ones and new clips. Sounds like you have the inside clip u-joints that are bigger than the outside clip u-joints. Almost all Pontiacs came with those joints and in the 70's you're never sure what GM was doing!

Another reason to use .050 lift numbers is it allows you to make reasonalbe comparisons of mechanical and hydraulic cams because it removes the valve lash variable which can be as much as .030 on the exhaust of an older cam and as little as .015 on the intake of a modern grind.

"Advertised" duration cam only be used to compare cams if they are all "advertised" equally. For instance with SBC cams, Crane specs their cams at .005 tappet lift for advertised duration, and comp specs theirs at .006, while GM specs their cams at .001". That is why a compareable Crane cam seems "larger" than a comp to get equal .050 numbers. GM cams for a 69 Z/28 is something like 345/345 advertised duration, but .050 is only in the 250 range. .050 is the industry standard and is quite useful in comparing cams, and like James said, the closer the .050 number is to the advertised number, the faster the ramp COMPARED TO ANOTHER CAM THAT HAS THE SAME ADVERTISED DURATION POINT! There is also a law of diminishing returns in effect. The ramp speed can only be so fast before exceeding the design range of the tappet assembly. Thus the high failure rate with the early Comp Xtreme energy cams... Not Datsun cam specific, but hopefully sheds a little light on the subject.

Small differences in backlash won't make a gear set wear any more quickly. They are designed to work within a certain range, and as long as you stay in that range you will be fine. This can be verified with a dial indicator and confirmed with gear marking compound. One danger in modifying the setup with gears that are run in to each other already is the possiblity of introducing a "whine". Usually not much of an issue, really. I haven't really experimented with the r200, but you should be able to find a clean one cheap if yours is worn out. I've even toyed with the idea of trying to preload the side gears by increasing the thickness of the spider gear bushings and having a "pseudo" Phantom grip. Having blown up somewhere in the neighborhood of 6 half ton truck 12 bolts (they REALLY don't like 35" tires...) I have done both new and used gear sets, swapping housings and diffs multiple times. They are really pretty forgiving all in all. All told I think I have put together more than 25 diffs now including 3 in a mid 10 second Firebird. (And no, they didn't blow up, he just kept chaning his mind. 28 spline posi and 3.42, 3.73 with 28 spline spool and finally 4.10 with 33 spline axles and a spool.)FWIW, torque is the name of the game with the big Poncho (462), and with each gear change, the car SLOWED DOWN. With 3.42 and a 2800rpm converter it ran 10.69 ~125. He's probably spent another 10k looking for the 9's and he's stuck in the 10.30's. Something to think about if you do end up building a larger displacement "torque" motor. I really like working with the hypoid gear sets, they are quite interesting.

Small differences in backlash won't make a gear set wear any more quickly. They are designed to work within a certain range, and as long as you stay in that range you will be fine. This can be verified with a dial indicator and confirmed with gear marking compound. One danger in modifying the setup with gears that are run in to each other already is the possiblity of introducing a "whine". Usually not much of an issue, really. I haven't really experimented with the r200, but you should be able to find a clean one cheap if yours is worn out. I've even toyed with the idea of trying to preload the side gears by increasing the thickness of the spider gear bushings and having a "pseudo" Phantom grip. Having blown up somewhere in the neighborhood of 6 half ton truck 12 bolts (they REALLY don't like 35" tires...) I have done both new and used gear sets, swapping housings and diffs multiple times. They are really pretty forgiving all in all. All told I think I have put together more than 25 diffs now including 3 in a mid 10 second Firebird. (And no, they didn't blow up, he just kept chaning his mind. 28 spline posi and 3.42, 3.73 with 28 spline spool and finally 4.10 with 33 spline axles and a spool.)FWIW, torque is the name of the game with the big Poncho (462), and with each gear change, the car SLOWED DOWN. With 3.42 and a 2800rpm converter it ran 10.69 ~125. He's probably spent another 10k looking for the 9's and he's stuck in the 10.30's. Something to think about if you do end up building a larger displacement "torque" motor. I really like working with the hypoid gear sets, they are quite interesting.