An 11:1 piston (.125 dome) like the TRW L2166NF will get you in around 9.2, you can work with the heads themselves with some additional milling to get it as close as you're trying to the 9.5:1 number. Thanks, Gary in N.Y.68 RS 302 said:I want to achieve 9.5 to 1 CR in my 327. I am confused on which piston to use with my 76cc heads to get there. Any help would be appreicated.
If you already have a strong 327 rotating assembly, I'd personally go that route...you can get those 327s to RPM way up there too plus you'll have a bit more torque too. Don't get me wrong, I love my little 302, but I think I'd like a similarly built 327 just as much. Plus if you want that 302 to fly, you need a steep gear ratio and if you really want it to rev, you're going to need a high duration camshaft which really needs high compression to work best (see where I'm going with this). Guess I'm just asking you to totally think this through before you spend a lot of money on mismatched parts that only leave you disappointed in performance. As pdq67 has put it before "The General got the 302 about right from the factory". So I'm suggesting that if you want to really build a 302, build it like the General did with respect to compression, camshaft selection, heads, etc...68 RS 302 said:Maybe its just a bad idea and I should just stick with the basic 327 setup and go from there. I was hoping to build a higher RPM motor.
I can appreciate your desire for wanting a 302 and I think you need to pursue that, otherwise, if you're like me, you'd never be happy. I think you're on the right track. I think there's another way that you can make a 302 using a crank out of a 267 chevy v8, but can't remember the details...I bet you can search for 302 on here and find it somewhere. As far as using the 5.94 rods and 350 pistons, I'm not sure. I'm thinking that you'd want to use 5.94 rods with a 327 piston since the difference between the 327 and 302 stroke is 0.25". The difference between a 350 and 302 would be 0.5" therefore I think you'd still be 0.25" in the hole. Hopefully others more knowledgeable than me will chime in.68 RS 302 said:Well I got a 286H cam with 3.73 gears and a 3500 stall converter. So I believe I am on the right track. I just need to know what rods and which piston to get the right CR. I have the World Torquer heads (76cc) with the large valves. I know I need a domed piston I am just trying to figure out which one for sure so I don't end up with parts I can't use. I love the 327's but I have never owned a 302 and I really want to build one. I guess if money were a real concern I would have just kept what I have. I am not interested in owning a 383 or something else, I want to build me a 302. I really appreciate all of the input and I have been reading everything I can. I read one post on another site that all I need is 5.94 rods with 350 pistons. Is that right? Shouldn't I need a 283 crank with 5.7 rods?