How to get 400 hp out of 1971 340 .30 over

RustyRatRod said
The easiest and most cost effective way is to build a stone stock 71 and back 340 with forged pistons and put a 150 plate shot on it.

Initially I believe this is true but the fun factor has to wear on you over time. $$$ Especially if you are heavy footed. I’m sure someone has done the math. Spray ain’t cheap.