Quote:
Originally Posted by luxeryvic
im not goin to buy new heads i dont want to spend much money on a 305 especailly when i have a spare set and can play around with them
ok so how do you figure out the combustion chamber volume and the compression ratio i have now? and there dog dish pistons does that effect it
then with that info how do i figure out how much materail to remove to bring it to a better compression ratio for more power?
also is this goin to be worth much more power? and is it right that 350 heads have bigger valves
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350 heads have bigger valves, AND bigger chambers. The former is good, the latter is BAD as it reduces compression. Most 305 heads have 58cc chambers, later 350 heads have 64cc chambers. You also have to worry about valve-to-block interference with some 350 heads with 1.94 or larger intakes. 1.94 is pretty much as large as you can go, and valve lift factors in here too.
A good set of 416 heads can be reworked to allow the use of 1.94s on a 305 (the 416s are 305 heads with 58cc chambers). They won't flow as good as the Torquer 305s I mentioned above, but it is what it is.
All else being equal, 416s are your best bet. These came on H.O. 305s from the late 70s through the mid 80s.
You can use steel shim head gaskets in place of FelPros, along with minor milling of the heads to achieve decent compression. Just keep in mind what I said above about warpage and cracking with these lightweight casting heads.
Typical compression on a standard (LG4) 305 is around 8.2-8.5:1.