340 Rebuild "Musts"

yellow rose said

Really? I have been running measured 10.5:1 and higher on iron heads and pump gas since 1982. My personal car is 11.08:1 (actual measured) on iron heads, on pump gas. If I change the head gaskets it will be 11.25:1 and still run on pump gas.

The compression ratio/iron head/street car/pump gas myth deal should have been long dead but evidently, it's still alive and well.

It's like we are stuck in 1986 again.

Click to expand...

I know that you are running 10.5:1 or higher on iron heads da dada on the street, simply because YOU know your shxxt (or most of your shxxt) like no other, and you are very confident in it. There is absolutely positively nothing wrong with that. That is the way engines can be built when you know what you're doing and when you have the means and knowledge to check stuff and troubleshoot when something's off.

BUT, the OP is asking advice as a novice, and he probably does know about 5% from what you know... so it seems much smarter to give a bit more conservative advice. That doesn't exclude basic machining like boring, decking, double checking evey measurement and such... ok the rest has been said by others.

Sometimes it's good to stay somewhere between 1968 and 2017.