Bummed out

No, the 6.1 and 5.7 have the same stroke, the difference in displacement comes from a a larger bore.

The 5.7 has 3.920" bore while the 6.1 has a 4.055" bore.

Stock stroke of both motors is
3.578" Stroke for 5.7L and 6.1L
3.795" Stroke for the factory 392 or 6.4L
4.050" Stroke for the Manley Crank
4.080" Stroke for the K1 Technologies Crank

I'd feel comfortable running the cast crank to around 550 HP in a street car that is going to be flogged for some Saturday night drag racing. The 6.1 stuff is good to around 700 HP. Though if I were like Uhcoog1 and going to road race the motor, I'd also upgrade to forged rods.

Regards,

Joe Dokes