As far as I know, Quaife is about the best thing that'll ever happen to a Solo2 or Road Course Junkie, but for occasional Drag Racing, unless you want greater peace of mind, the stock diff may actually put a hair more power to the ground and as I've already mentioned, you may not see a single difference in 1/4 times w/quaife. This thought about Quaife causing a tinge less power to the ground was not that of my own and I personally haven't tested this theory, but It came from a VERY Reliable source, most old timers here will remember him