Originally Posted by webracin

I would have to say that Toasty is probably right. The reason it's different is due to the Heavy Duty Differential. So, (and I am just throwing numbers out) if 30% of cars use the GTP shaft, and 70% use the GT shaft, the cost for manufacturing the shaft will be split among each group, and since there are more GT's out there than GTP's, its cheaper for the GTP.

webracin