The PowerPack IRS is here!  This heavy duty center spool is designed for the Big Block "J" frames. 

Bolts on and puts the sprocket in the proper alignment with the output sprocket on the 40 series gearbox.

The PowerPack IRS spool can be fitted with either a #420 or #530 sprockets with 6 X 5.25" bolt pattern

and 4.563" center holes.  (Sprocket is not included)

Uses readily available 1990-1993 Mazda Miata Axle CV axles. 

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