Need a little help with my engine combo. I bought a used 306 gt40 crate motor w/o heads(originally had aluminum x heads). It has an e303 cam. Since it had no heads, I bought some afr 185's and comp 1.7 roller rockers. I have an edelbrock performer intake and a 650 holley. I'm open to changing the intake and carb if i have to but i'd like to keep everything else. (I know i need to measure for pushrods) WIll this combo work? I'm hearing that 165's might have been better but it's too late for that now. Unless the 185's just are not going to work at all. Any advice is appreciated. Thanks
Yes, it will work. To what degree for it's "best performance", is questionable. This is not to suggest it won't work at all, just no to it's best potential.
Now, If you stroke to a 331 (333 w/your.040) and up the CR to 10.0, add a Performer RPM, you'll "greatly" improves it's potential. With those 185 heads on a smaller breathing 306, you're going to be sacrificing torque potential, which is what you feel in your butt and want in a decent street warrior. I'm only running 170 TW heads, a 10.6 CR, and a nice cam in my 333, and it's making 392 RWHP @ 6100, or so, with 400 RWTQ at 4200.
I realize this is after-the-fact. But, with more research, you would have purchased differently.
Good Luck in sorting it out.