Hi, I've got an 6 speed conversion on my gc8 with stock front gc8 drive shaft and r180 rear drive shaft, What are the hp limit of the front gc8 drive shaft and rear r180?.

 

Depends on mechanical sympathy. Launches

 

wouldn't have thought much to worry about roadwise but heavy 1/4 mile launches is anyone's guess.
I have the 6 speed conversion on my newage wrx wagon which is a heavier car and was ok up to 460hp launching at 4900rpm but snapped a front driveshaft when pushing 500hp using nitrous. The sti items are much beefier by comparison.
Trev