I just bought a 74 with a 454. Im looking into buying a new hood. Then I will probably be installing the edelbrock high compression heads... they have a whole kit, cam, heads, intake, and carb... they claim that it will pull about 540 horsepower at the crank... does anyone have this or have you heard otherwise... Im new to the old school power... I have been dealing with newer cars and fuel injection computer tuning ect... I know nothing of carb engines... Same concept I guess. I have also been looking at upgrading the suspension and the rear end with a 411 rear end from ecklers... the car is automatic will this be too much for street/strip (mostly weekend street) any and all info you guys have will be much help

 

alright if knowbody has any comments on this... then how about some ideas of getting around 500 hp in this car best bang for the buck...

 

Your LS4 is very similar to my 71 LS5 back when mine was stock. Have a look at my website. I have dyno graphs stock and with various mods. It should be noted all the dyno runs were made on what was later determined to be a very unhealthy short block. 4 broken piston rings, wrong pistons, worn/wrong rings etc etc. Still made 390 rwhp (close to 500 at the crank). I'm currently reassembling the motor and expect it to do better.

 

great info.... this is exactly what im looking for...thank you

 

I also have a 74 with a 454, mine is an auto. coupe w/ 3.08 rear. I purchased the car last summer and want to build it into a fast daily driver. So far, I have tackled the body and interior. I also have a suspenstion kit with Bilsteins, larger sway bars, and front and rear monosprings on the way from VBP. After that will be the engine. The numbers-matching LS-4 is mostly stock, but has been upgraded with a mild aftermarket cam (don't know specs) and some "head work" (not sure what this entailed - it was performed prior to the previous owner getting the car). It runs OK but does not make much power over about 4500 RPM and pings badly even on premium fuel. At this point I have narrowed my plan down to 2 possibilites, which will depend on the condition of the shortblock: upgrade the stock engine with bolt-ons (Edelbrock Performer TBI heads with 100cc chambers to raise the compression, aftermarket HEI conversion distributor from Ecklers with mechanical tach drive, 750 or 850 vac. sec. Speed Demon carb. on factory LS-6 manifold to keep it under the stock hood, and Hooker Super Competition headers, probably see how this combo runs with the cam in it first then possibly upgrade to hydraulic roller later)....OR....pull the LS-4 out, set it in the corner of my garage to preserve its value, and drop in a ZZ502. I entertained the possibility of having the LS-4 rebuilt, but for not too much more money than a high-performance rebuild I could have a ZZ502 with all the heavy-duty internals, 567 lbs-ft. torque and a 12 month GM warranty. I will be interested to know how your project proceeds.

 

The biggest problem with stock mid-70's engines is the low compression ratios used for emissions purposes. If you rebuild your engine with pistons that will give you a higher comp. ratio you can really take advantage of the performance kits. I don't think you will come anywhere close to the kit's claimed horsepower with stock pistons.



Rick B.

 

Your website and build-up of your beautiful red 71 were most impressive and very helpful. You must be an engineer by trade.

 

Thanks. and yes, I'm an engineer.

 

my dad is an old school muscle kind of guy... he thinks i should do all bottom end and just leave the stock heads... he said with a good bottom end and high compression pistons and a good cam manifold and carb... the car will be real quick... but im still considering just a top end build with the high compression heads from edelbrock.. they say it will bring the compression to 9;5;1 i just cant imagine edelbrock with the name they have made in performance saying it will push over 500 on a stock bottom end and it not being true???????? but i dont know thats why im asking... now im planning on using the manifold that will require an aftermarket hood but still debating... i will start taking some pics and get them posted soon.. im thinking this will take me about 6 months