90mm billet tensioner idler now available

[thump_rrr]

Due to customer demand a 90mm billet tensioner idler is now available as well as the standard 76mm.
There is an additional cost of $12 for the 90mm instead of the 76mm for a total of $377 + shipping.

 

[stangzilla]

so which idler pulley would i need for a 10psi/3.375" whipple pulley, the 76mm or 90mm?