Hey everyone, after some researching, it seems that the 307 in my 68 Impala is not exactly the ideal baseline for a decent motor buildup. It seems that swapping in a 350 is the better option. Unfortunately, a motor swap is not in the future so I want to make the best of what I have. This is a completely stock 307 with a powerglide tranny and the car is just a street cruiser. Two things that I've read about in a number of posts have been about the bad flowing heads and the low compression. So I figure better flowing heads would be a good place to start. I was thinking vortec heads and a RPM intake manifold. Other folks suggested 350 heads. I think I'm on the right track but just thought I'd throw this out to you experts. Thanks for any input.