Yeah that was a pleasent surprise for me. They increased the size of the windage ports throughout the block that allows air to move in the block something like 70% more than the LS1 block. Hence, the engine can rev quicker. Your testimony is proof that it all adds up!
1991 Formula Firebird
2001 LS1/4L60E, 3.23 posi rear
Comp XE 216/216 .577/.577 114LSA cam
918 Springs, hardened pushrods
Yank SS3600 torque converter
PCM reprogrammed for cam and converter
3" exhaust
BRM Adjustable torque arm, tubular read LCAs
Spohn Adjustable panhard bar, front steering brace
Spohn Subframe Connectors
4th Gen style wheels
Bilsteins sport struts and shocks