RE: OS .91 FX in a classic pattern?
Hi Tommygun,
I don't have enough info.
The un-piped 90 will have about the same ponies as the piped 60, but at different RPM.
Try running an 11-10 or 11-11 rather than the 11-7 you probably had onn the old piped 60.
Is that what you had on the piped 60?
Like I said ... need more input!
Dean P.