AAaaaa, how did it get sore in the first place ? More to the point, how heavy is that 401 anyway ? If you look at the charts of engine weights, surprising to learn the 50's to early 60's Cadillac's are not all that heavy yet no one ever sees a Caddy engine in a hotrod. 1963 Cad engine is 390 ci and not all that bad on torque. We put one in a 1964 Ford 1/2 ton.