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Topic Review (Newest First)
09-29-2003 03:58 PM
FiefSS i put wrong number excuse me

3991492. Another good performance head. They were found on 1970 LT-1 engines. They had 2.02/1.60" valves, 64CC combustion chambers, DO have accessory holes, intake port volume should be 161CC's, exhaust port volume should be 62CC's. These heads have double hump casting marks. This particular casting head was also available as an "over the counter" head from GM in straight or angle plug configurations.

it would be those. 2nd off its a gm over the counter cam, nothing special. Im not trying to make it any better than it already was in the early 70's.

I know I have tons to learn thats why im not trying to mix and match stuff now. Im goin with a something that has already worked b4, and all i wanted to know was what carb to go with. and i was a bit off on the rpm, 290hp claimed at 5800rpm

thx for the advice though ,i will pick up one of those books
09-27-2003 08:14 PM
DoubleVision Honestly, I`ll tell you what I think. I think you got a lot to learn as far as hot rodding goes, you need to invest much much time (a year at the least) into reading books such as "how to hot rod the small block chevrolet" or "Max Chevy Performance" your engine idea is not a very realistic one, I don`t know where you heard the 302 made it`s power over 7500 RPM, if that had been the case from the factory the car would have never been streetable. 302`s are not low end torque engines, and to run a cam that will rev over 7500 RPM and stay together will require a very heavy duty valve train, and I`m talking good stuff, such as valves, springs, guide plates, rocker arms, heat treated push rods, hardened locks and retainers, your not gonna take a stock set of heads and bolt them on and expect to rev it to hell and it stay together, valve train dictates with a iron hand how high a engine will rev, and at that RPM you have to have a bottom end that will take revs that high and hold together, stock rods aren`t gonna cut it. 12:1 compression,, lets see, that says right away it won`t be streetable, unless you plan on running 108 octane race fuel, it`s not gonna run on pump gas from the nearest gas station without detonating itself to death in a very short order, if you don`t believe what detonation can do, the late Smokey Yunick said "detonation has destroyed more engines than I could ever count, if I had a nickel for every engine that blew from detonation i could buy a small country and retire"
462 heads did not come on LT-1`s, there last production year was 1967 and they came exclusively on 327`s.
to run the car with that kind of RPM you must be planning on running 4.88:1 gears, that`s the only way the car will have any low end power, high rev engines have to make up for there lack of torque with low gears.
Not trying to be nasty, but hot rodding is not something you learn over night from old stories on what cars in the 60`s did, technology has advanced a hell of a long way since then, and I think many stories from then get greatly exaggerated over time from one person to the next. I`m only being honest and telling you this because no one should jump into any project with goals like you have and not know how to get there, if you go on to build this engine the way you want it to run your gonna make a lot of junk pieces getting there, you can`t sneak up the horsepower ladder in little stages, either you stay with stuff that can handle the power the engine makes, or you do it right the first time and spend the money needed to make a engine perform this way the first time and you`ll be money ahead, blocks, cranks, rods, and etc get expensive over time after you end up replacing them due to blown engines from trying to sneak up the ladder. Engines either do 2 things, either they make power down low, or up high, there isn`t a engine that will make both, and I`d rather have a engine that makes lots of low end torque than have one that revs to hell. Bob Glidden won all the championships he did from Torque, if you go back and watch and listen to his car running back in the day, the exhaust note is clearly different from all the rest, he didn`t have to rev it to death to win. torque is what you feel, it`s what pushes you back in the seat, it`s what moves all that sheetmetal around, not horsepower. engines that make power in the low RPM band last a lot longer, high revvers wear parts out quickly from continued high RPM flights. so there you have it, that`s pretty much the basic start on how things work, read up and learn more, then build your project, you`ll be happier you did and so will your wallet.
09-26-2003 09:39 AM
FiefSS The cam is just a 69 302 offroad cam that was purchased when the crate engine was. The specs for the cam are here
last one on the page. Lifters are just the stock solid pieces.

The heads are 426 double humps from a 70 Lt-1. Intake and exhaust valves are slightly larger than stock I have been told.

Im thinkin the 750hp from holley would be a good choice? with the extra info what do ya guys think?
09-25-2003 07:33 PM
78 monte
Originally posted by Jmark Q-jet all the way!!!!
He wants high performance,not high blood pressure.
Allthough they do make good wheel chucks in a pinch.
09-25-2003 07:31 PM
DoubleVision I`m in agreements with 1BAD80, not enough info here. Although, I could say much more, I`m not gonna, I would rather wait to see how this turns out. another one tryin to sneak up the horsepower ladder. best of luck,,, your gonna need it.
09-25-2003 07:03 PM
1BAD80 [QUOTE]Originally posted by FiefSS
[B]its gonna have to pull over 7500rpm since thats where its power is made. Intake classic edelbrock tarantula a winner for a 302.

Can you Please tell me what cam you have?
With a stock bottom end, and AT OVER 7500, double hump heads trimmed so compression is around 12-1 to 12.5-1.

This is one great motor, how much HP do you think it will make?
09-25-2003 06:20 PM
Jmark Q-jet all the way!!!!
09-25-2003 05:45 PM
FiefSS its gonna have to pull over 7500rpm since thats where its power is made. My dad has had plenty of carbs on it from old 450cfm 2 barrels to a 800 something 750 seemed to be the best so we are gonna stick with that. Even if the carb has been sitting for like 18 years and even when it was put away had a ton of miles If i were to rebuild it would it still be as good as new? And how do I clean this thing off? Its mighty dirty

well then my dad forgot to mention he didnt know what the carb was, and as it turns out its just a 585 so then i need new one i guess!
09-25-2003 03:19 PM
Tech @ BG You could go with either a 650 or 750 Mighty Demon on your combination (Both less expensive than an HP).

A 650 Would probably give you better acceleration, and drivability especially with the large exhaust system.

The 750 would pull harder if you turn the engine over 7500 RPM
09-25-2003 11:08 AM
cobra 28 If I were you I would go with the DEMON carb more smoother and better performance than the Holley would ever think of being. And unless you have over 400 hp I would go with their 650 size carburetor. TO many people think they need a 750 when they do not, plus there 650 is larger than the holley 650. Do not use the 750 Dominator not worth having on the street.
09-25-2003 10:12 AM

Go get a proform main body and clean and rebuild the 750 that you have, you will be out only around $120 or so for the main body and gaskets and will have a fresh carb that runs great. I have one on my 383 and love it.


09-25-2003 08:39 AM
1BAD80 I agree with 78 monte rebuild it, not hard to do if you follow the instructions.
Holly Rebuild and Adjustment Instructions
If you need any help while rebuilding please post the question.
09-25-2003 12:44 AM
78 monte Why not rebuild the old 750???Was it a double pumper??
Pretty much what ever you buy will need to be taylored to your motor anyway,so I would just(unless its shot)rebuild the existing carb using propperly matched power valves,then jet it and play with ecelerator pump cams.
If you do buy one I'd say just a 750 double pumper.I think the factory Z28s came with a 780 DP.
09-24-2003 08:47 PM
jrhoss the 750 dominator needs a special intake to work properley and 2-300 more than a normal 750. a demon carb would probly work well if the motors pretty stout, but again its expensive
09-24-2003 06:43 PM
FiefSS Its gotta be "streetable" in a sense but its not gonna run nice, just dont want to go overboard to the point it hurts the engine more than it helps
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