I've got a GT3251 to try out, most of the GT32's are with a 55 wheel, this one with the smaller 51 spools instantly to 10#!!
Its on my TTA with stock tranny...should have some results from the track in a few weeks.
I beleive the 32 and 35 refer to the exhaust wheels. I had a GT35 to try out a while back since it was the next GT step up from the 32, and it spooled terribly with an 82 and 63 exhaust housing. It had a 61 compressor wheel. Now I have a GT61 with a 31E garret style exhaust wheel and it spools much better with a 2700 stall convertor.