Join Date: Nov 1999
Location: Where the Navy sends me...
Which 14" Brembo setup are you referring to? I know there used to be a conversion setup from Vintage Venom to use the 14" Brembos from the S197s on Fox and SN95s, but I thought Vintage Venom had disappeared a while back. Edit: I see Fully Torqued Racing is still offering kits for the 14" Brembos.
Anyway, assuming that's what you're referring to, and assuming those kits are still available somewhere, I would say it will be a significant upgrade for track duty. The 14" Brembo setup is not only bigger rotors, but also significantly bigger calipers and pads. Not that the '00 R setup won't work, but the newer 14" setup offers more of everything. Sounds like you've got plenty of GO!, so it's always good to have plenty of WHOA! to go along with it.
As for 17"s vs 18"s, it's worth looking at tire selection in the sizes you'd be thinking of running. For now the 17" R-compounds are pretty much all still available, but with wide 17" street tire options getting scarce, I'd be worried that 17" R-compounds will follow that same trend.
'89 GT convertible, N/A 357W, MM front susp w/425# coil-overs and Koni D/As, MM TA/PB rear setup (Koni Yellows, 390-430# springs), Stoptech 332mm / 12" Baers, MM 6 point rollbar, Maier 1.5" flared fenders & quarters, 18x9.5" front/18x10.5" rear Enkei RPF-1s (street), 18x10" CCW C-10s (track), etc...