MTI has just finished it's first GTO with a new Prototype engine. The displacement is 455 cubic inches using a Darton MID block. Final rear wheel #'s are 519 rwhp and 527 rwtq. Baseline stock numbers were 291 rwhp and 308 rwtq. That is a 227 rwhp increase! Needless to say, this car is amazing.
Oh, BTW, this is through ceramic cats and a very small cam...