What is a 408???

Take a 360 and bore it .030 over, nice set of flat top pistons (10.8 app Comp), Scat rods (budget) H beem rods if you want to spend a little more, polished stock crank, ProMaxx heads, port matched Victor 340 intake, 750-850 Holley carb, .520 Racer Brown cam. It will run on 93 pump gas and probably put out 350-400 horsepower easily