Opinions on a 340

I don't understand why everyone insists on giving you bad info. It most certainly CAN be done with 8.5:1. You simply have to know how to do it and which parts to use. More importantly, which parts to AVOID. 350 plus HP is easily within reach of a low compression engine, with ZERO chance of having trouble with pump gas. It's simply not true that everything has to have 9.5 or more to make reasonable power.

I've balanced and blueprinted more than a few "low" compression 340's, stock everything except milling .020 off the J heads, 1.88 intake valves, including cam intake and carb. They fly. And you can use pump gas all day long. The next engine in our 67 Barracuda will be just that. As for being 5% more than a 318, dream on.