Hello I have a 1974 big block 455 with 1968 430 iron heads was wonding how much of a difference performances will the TA aluminum heads make as far as horse power since these heads cost a lot?
I'm sure others will chime in but it's not about what one part will do. It's about the combination of parts. With that in mind, good heads are the single most important factor in building a strong 455. Plus they really hold their value should you ever decide to sell them. Cliff
Dear Al68buickgs, Cliff, and V-8 Buick engine experts, Cliff makes the key observation. If you simply replace the OEM heads with aluminum heads the only thing you are achieving is a reduction of weight. Aluminum heads allow you to switch from an exhaust manifold to headers which will improve your engine's breathing and that will improve horsepower. The other thing you can do with aluminum heads is increase the compression ratio, but that involves other engine changes. If you want more horsepower, you need to come up with a new design. You might want to start a thread in the big-block topic: http://www.v8buick.com/index.php?forums/street-strip-400-430-455.6/ That's where you'll find the guys who are experts on the possible trade-offs and the best way to get the most bang for your buck. Cheers, Edouard
There are several aluminum head options available from TA, from very basic replacement(Stage 1 SE) of your oem iron heads, to full race style heads. Even the Stage 1 SE heads alone are a decent improvement over stock iron heads, without other upgrades. TA indicates a typical 50 hp gain over stock oem. Out of the box they flow better than oem heads. The upside also is they lend themselves to you doing additional upgrades that would be less effective with stock iron heads. The question you need to ask yourself is what is your purpose with the car, and what kind of budget do you have to work with. Performance costs money, more so with a Buick than a more common make. As Edouard mentions, the Street/Strip section of the board is FULL of existing information to help guide you. http://www.taperformance.com/PDF/TAPerformance_Catalog.pdf
The TA heads with entry level porting will vastly out flow your iron heads. To take full advantage of their potential, you will need to increase your static compression to at least 10:1. Definitely worth doing as heads are the foundation for big power. They will enhance whatever you do to your engine going forward.
If it's a factory '74 shortblock, the static compression ratio will probably measure somewhere around 8:1, if that. The TA heads would still be a nice improvement. Devon
