I've pondered upsizing the TB and it seems it's not a huge restriction. I'd get a hold of rick (Buckshot77) and get an SVT optimized TB. It's $57 or so (157 at first, and when you send him your unoptimized TB, he gives you $100 back).
Derek
Scion xB 5-spd
Previous: 2000 Silver Frost SVT
Please share the road with cyclists.