I laugh at everyone that says the 5-6 conversion is not worth it. Almost everything that is done to these vehicles are not worth it-- tuners, exhaust, tires, wheels, lifts, bumpers and etc. To them, nothing is worth it, except what they want. There is no payback on anything.
The conversion is expensive and probably overpriced, but Suncoast has figured out how to make it work, and it does work. They are getting paid for the R&D. The kit is a modified valve body and a reprogrammed TCM, all exchanged back to Suncoast. This is the only way to get 6 speeds out of an early 5 speed Allison-
It may make a difference in fuel economy, but the biggest plus is the lower cabin noise at freeway speeds. When you go to T/H mode, it blocks out 6 gear. I doubt you will be able to tow in 6 gear anyway, unless you have a small light traailer.
Chevy 04.5 LLY, 2X, shell, XDR, MikeL Heavy duty up-grade, 6spd, TransGo, deep pan, de-badged, 65 Gallon replacement Aero tank, LBZ-mp, Kennedy pump, shimmed, Pre-fuel filter, tow mirrors, BU cam, gauges, GPS, Sirius, bags, custom grille, fender vents, HD trans cooler- Curt front hitch, footwell lights, load lights, Studs, head gaskets.
Last edited by jc1843; 02-11-2011 at 08:59 AM.