4,500 HP Billet LS, Pt.1 - Block Our previous billet LS engine design was shown to run well for Marcus Carew at 4,000 horsepower. Thanks to the extreme processing speed of his Emtron ECU, we were able to see some flexing of the crankshaft at that power level. While not problematic at 4,000 hp, our new target was going to be 4,500 hp so a redesign was required. The solution started with a BRE-custom, Energy Manufacturing billet LS block. Main journal diameter was changed from the LS standard 2.55