talk to Patrick,Prosystems.his price is right.
personally i don't buy tyre size guff.it is only a factor to set up the dyno.though some 4.10's won't hurt with that cam
really i would hope to be making some more power and if it has all gone by 6000 i would be looking at your whole fuel system
good luck

Tex

New best ET 10.259@129.65 .
New best MPH 130.32
Finally fitted a solid cam,
stepped it up a bit more
3690lbs through the mufflers
New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm
Power by Tex's Automotive