I've never run TTI's at all, but I have run 2" Hookers & 2" Heddmans. The Hookers gave me about 2" more ground clearance vs. Heddman. Hookers had 1 slip tube & all 4 Heddman primaries were slip tubes. Hope this helps at least a little.

70 Roadrunner convt. street car 440+6, NOS, 4-spd, SS springs '96 Mustang GT convt. street car '04 4.6 SOHC, NOS, auto, lowered "Officer, that button is for short on-ramps"