This is a castle copperhead 2250 on 3s, largest pinion I counld fit on an ax10 tranny after grinding out the holes.
I had it barley warm in the 5 months of owning. This dolley is 35-40Ibs. Off the line I can't feel it, once I get 1/8-1/4 throttle, I can feel the weight but it never struggles...