Discussion in 'Buick FAQ' started by Nicholas Sloop, Jan 25, 2007.
I'm guessing stock with headers & intake I'm somewhere around 400 or so...
Let us know your trap speed in the 1/4 mile and vehicle weight, and we'll know.
3900 lbs with me in it best so far: 13.7 @ 98mph.. that was with the stock 350 converter.. I put a 2400-2800 converter in it after the season was over. I did a bunch of other small stuff... I hope it still hooks good..I hope to break 100 and pick up .50 sec.. maybe that is asking too much.. I'm also having another carb built for the upcoming season..
That's around 300 hp at the wheels, so your estimate's not far off.
Cool... not bad for a junkyard motor
Everyone calls these heads boat anchors, I get it. That is the concensus. But doesn't that really depend on the application? I mean, If you are on a track trying to get every last drop out of your motor, then they are junk. But if you are just building a weekend cruiser that sounds mean and gets up and goes, I would have to think that with a good cam and pistons, and decking they would work fine.
The 75-76 heads are open chamber. That means the combustion chamber is the size of the bore. Closed chamber heads for our engines are much more efficient. It's a no brainer to just get earlier heads to use on the 75-76 blocks.
No, none of this applies to nailheads.
i have a 1975 455 with 75 heads .i have now been offerd some 1970 heads from a gs . i am rebuilding the engine at the moment. its been bored +40 i have 9.5 1 pistons a TA 288-94h cam edelbrock inlet manifold TA shorty headers and a holley 750 double pumper .what kinder hp will i get with the right heads. also would the early heads fit on my 75 block . by the way the 455 is going in my 1979 trans am. is all this compatable thanks kev
can any one help thanks kev
Yes you can use the 70 heads on the 75 block. This page explains the only concerns you can run into when using different year heads on different year blocks.
NONE of the problems are insurmountable. I would get with the machinist and make sure that your final compression ratio is at least 9.5:1, 10:1 preferred. The machinist can adjust the deck height and/or mill the heads to make that happen.
When it comes to HP, everything is head flow. To that end, I would budget for some porting if you can. I try never to predict how much HP an engine will make. I really don't understand why anyone asks to tell you the truth. Build it with 10:1, and good flowing heads, and it will scare you when you lay into it:grin:
hello all. did not get the early heads. i have bought a pair of edelbrock heads and the edelbrock inlet manifold. will this be a good combination with the 9.51 pistons and ta 288-94h cam. thanks kev
Larry70, tried to access the "useful casting numbers" but i get an error message that says --Invalid Attachment Specified,etc. Not sure what this means. Will try again later, would like to know these valuable numbers. thanks
Good stuff purchase a 68 Buick GS 400 the guy put a 455 out of a 74 year Buick with 68 430 heads with TA oil mods plus a TA 413 camshaft temp runs cool and oil pressure is great I'm please with the engine only thing I change was the Demo 850 manual carburetor to a Holley 750 electric chock since I don't run the car on the track only street cursing?