Originally Posted by Gav Diamond

Going on Rods diff ratio of 3.54

Tremec in 3rd (ratio of 1.28:1) at 8000rpm is 124.90 mph
Tremec in 4th (ratio of 1:1) at 8000rpm is 159.88 mph

Done on the tyre size of 215.40.17, understand what you mean about the road slicks overheating on the rollers as have seen it first hand.