Whats The Maximum Horsepower Im Going To Get Out Of A Pontiac Lemans 400 Ci Engine

Posted in Crank, Oil and Piston
  • To all the gear heads who know alot about muscle cars what is the maximum horsepower i can get out of a 78 lemans v8 400 ci? i already have the 400 ci turbo trans with a shift kit on it but i havent made the effort to change the rear end to positive traction and put the gears and either a 9 or ten bolt on? what is somethings i can do to increase power comming from the engine without putting a blower on or supercharging it if thats possible? should i put new pistons and headers on or that doesnt really matter?

    There are 2 Answers for "Whats The Maximum Horsepower Im Going To Get Out Of A Pontiac Lemans 400 Ci Engine"

    1. Sam says:

      no you want to focus on carb, intake and cylinder heads (most important). Headers are helpful too… pistons are not worth taking the engine apart for.

    2. Fastbob says:

      Sam is right, also focus on the valve train and cam. Changing pistons to higher compression will make more HP, but will require premium fuel and in extreme situations racing fuel. If I remember correctly the 400 is a small block Pontiac motor. 300HP should be very easy and streetable.