Well I know how my O.S .12tr runs, and it really can't keep up with the faster guys. But my driving could also have something to do with that. On the back straight head to head they will take me. Depending on the engine, depends on how fast I get ate up.
. I think the Mt12, one of the guys was using was pretty awesome. Judging from the specs on the OS .12tr turbo, I'd say you would do better now and in the long run if you go with one of the engines that NitroAddict suggested. Lunatics is hoping to get a national race at his track next year and that turbo won't be allowed. I think the MT12 would probably still beat it if you guys dragged tc3 vs tc3.
But that's just speculation. I haven't seen an O.S. 12tr turbo out there, yet.