I put my money where my mouth is and ordered a SunCoast.
Here is why:
1) Plan to tow up to 7,000 lb so I can haul my Antique Tractors.
2) Want the Pump fix (Step 2) for the front pump which is included in the newer Transgo Shift kits (Note 10/10/09 Copy Right Date on document){Sonnex also has a fix for the same valve in the front pump}.

3) The front pump fix (Step 2) included in the newer Transgo kits has eliminated any and all shuddering with SunCoast converters. If your Transgo kit does not have the valve in Step 2, you do not have the front pump fix.
4) SunCoast steel billet back provides stronger mounting lugs, plus smooths out the engine by having more fly wheel mass. Now SunCoast owners, you know why the engine is smoother running.
5) Plan to go with SunCoast TCM reprogramming. SunCoast shipped out 4 Dodge Cummins reprogrammed TCMs when I was there. Ron Wolverton's son's Ram 1500 has been running for a year with a 545RFE that has been reprogrammed to run as a SIX SPEED. Bye Bye F37!!
6) Since I will have a strong Torque Converter, I will be able to have the TCM to be tuned to the optimum performance for a DIESEL ENGINE, not a patooie gasser. I want to have my converter locked at 1200 RPM and not have it unlatch at 1600 RPM.
Ron Wolverton ordered a J8/Euro Converter they are going to open up to see what it has inside. I will report what is found next week.
For those of you who want to beef up your Cummins to 800HP, Ron has a new clutch pack going into his truck this week that can handle the extra torque. This clutch pack will fit into a 545RFE as well, but I have no plans to go over 200 HP on mine.