Just found an old poll about intake manifolds - sorry for posting a new one all over again. I'll get more to the point. I'd like a 450hp motor. - I'm willing to run 10:1 comp. (have easy access to 94 octane from Sunoco here in Ontario Canada). - I'd like a noticeable idle lope but it's a fullsize 68 LeSabre, so I need to concentrate on torque versus high-rpm horsepower. - I'll likely do an alum. intake (Edelbrock? Offy?) - I'm hoping to have enough in the budget for custom headers (unless anyone knows where I can get shorty headers for a 68 full size) and 3" Flowmasters. Anyone have suggestions for carburetors? I don't have an engine yet, but I have a line on a '74 2-bbl 455. What oiling mods would it need? Thanks!
TA Performance has shorty headers for BB Buicks. Not sure if they will work in a LeSabre though, check their website or call them. They can help you with cam selection as well. For street duty, the Edelbrock B4B and a good Q-jet is hard to beat. The '74 455 would be a good foundation for a build-up. It's block and front cover have improved oil passages, so you really wouldn't need to do much in the way of modification...just a new oil pump and booster plate would be adaquate, and maybe an oil pressure regulator. Probably the most important thing to do would be to replace the cam bearings with TA's grooved pieces. Good luck.:TU:
The engine you are looking at was low compression( 8.2 or less )with smog heads. Starting with that set up will start you a long way from 450 hp. It will be hard to make it up with exhaust, carb and intake mods. www.Taperformance.com sells shorties. The bigger the cam the less vacuum to run power brakes. More noise and lope comes from a big cam but perhaps a slower time between stoplights will ensue relative to a less radical cam. For the kind of driving you will lilkely do, you might want to reconsider.
modified q jet,stage 1 fuel pump, 3 angle valve job,bowl blending and a port match 118 cam headers dual plane intake, with 10 to comp, you should make 450+ h/p, and if you polish the combustion chambers and the top of the pistons it should not knock with 92 octane
The '74 heads still have a pretty good combustion chamber, so if you were thinking of replacing the pistons, they would be OK.:TU: If you were not, then keep looking. Cause like Jim said, that is a low compression engine. But that low compression is achieved through the pistons.
Thanks everyone! Pistons would certainly be changed - the chambers on the heads are still a fairly good size like BirdDog said, so I'd do the cleanup/valve work Kelly suggested on the stock heads. Last time I checked, TA didn't have shorty headers yet for fullsize cars. They had it on their future projects list, so I'll just have to wait and see. Man - it's hard enough when you fall in love with a Buick, I had to fall for a fullsize! Thanks Kelly for the hard facts - glad to hear the Qjet and 118 cam will do it. I'm going to try to get in touch with Dave Mongeon in Guelph Ontario for the build - anyone know him?
