318 For Fun

I think in terms of stock 318 bottom end you would run stock 318 heads, anything else in terms of aftermarket will have bigger combustion chambers dropping your compression ratio, if you can add higher compression pistons , you could run Edelbrocks etc. the cc size of the chamber is what you'd need to know OR get into the porting of the stock heads like some do here.

Open chamber LA 318 heads cc at 67-68 ccs while the 340 heads cc at 68-72 so its a big drop in compression. I was going to run 360 heads on my 318 untill I realized the drop in compression. Heads are a concern and do you research but you may find running the stock heads is the way or maybe with some porting for the velocity you are mentioning.