what does 60mm mean?

A 1.05 A/R on the turbine side is a bit large. I would go .96A/R max on a twin setup, and honestly smaller for a stock cube car.
As for big, I have a customer running Twin Y2K-88's....now thats big....lol
Jose
What spoolup would you see with 408ci...245/245 540lift at 114...full dual 3" exhaust with straightthrough muffs, 727 auto 3.21 gears, with the twin MP 61mm .68ar-ptims....think full (18-20psi) boost by 4000? Just asking.
Motor is smallblock mopar.


