Posted by T.L. (IP: 209.156.120.9) on December 18, 1999 at 23:47:40:
In Reply to: Re: 1974 Comet 302 V8 posted by Erik on December 18, 1999 at 22:10:43:
...'73 had 8.0:1 compression ratio (not 8.5)...351 heads will DRASTICALLY lower compression ratio unless you use taller pistons. Competition Cams sells new 1.84/1.54 valves that can be installed into these 302 heads...They still won't flow like DART or TRICK FLOW or EDELBROCK aftermarket heads, but will flow mUCH better than stock and would be much cheaper. His '74 302 has dished "smog" pistons but they can be changed if he wants to rebuild the motor. It is definitely worth keeping because these motors are not made anymore and in some parts of the country, they are deliberately destroyed by junkyards so no one can ever rebuild them...
: I would stick with that block, but if you can afford it go with better heads because the stock heads are ok for MPG but not really a performance head.If you can't afford aftermarket heads , then you can go with a 351 W head (only the ones with 1.84 intake) , or go with 289-4v heads because they have smaller chambers and increase comp. ratio, one head alot of people forget about too is the 68 302-4v (has 53.5cc chambers) and these heads are fairly cheap and will also increase comp. ratio quite a bit.As far as your compression ratio , I don't have the exact specs for 74 (all I got is 73 and 75, sorry) but this should give you an idea, 73 8.5:1 , 75 8.0:1.Hope this helps