I've been through every 302C Aussie cast iron head-related discussion on the planet and have come away without totally understanding the impact of putting the heads on a 72 351CJ. Some seems to suggest no real problems; others say too much compression for pump gas. I've also read that the Aussie heads have 58cc chambers, or 62.8cc chambers, or somewhere in between?
Anyway, here's my story. I've pulled the stock 4V OC heads off The Beast to replace a slightly-leaking head gasket and thought that this might be a good opportunity to rebuild the Aussie heads I bought a while back, but I'm concerned about the significant rise in compression ratio (~10.4:1?) using 93 octane gas. I'm willing to replace the cam (BTW, what is the max lift with stock FT pistons?) to reduce cylinder pressure so I can run on pump gas, but I want to maintain low-end grunt and response for the street. Otherwise, what's the point of making the swap.
FWIW, before the tear down, I check the compression and got a reading of ~165 pounds across the board. The engine has been rebuilt using .030 over flat top pistons. I have no idea what the cam is (yet), but I assume it's stock or near-stock specs.
So, whenever you have a chance, I'd appreciate any and all advice on whether I should proceed or whether I should abandon my Aussie head project for the time being.
Thanks for your time.
Regards,
Ron
#3336