This data is from Ron @ Suncoast.
New for 2008 are our custom designed billet stator series #55, #58 and #59.
This past year the tuners have made some huge power gains, with that said Sun Coast saw the need for more efficient fluid coupling and better spool up converters for big turbos. We have added 3 new converters the 55, 58 and 59 to our Allison torque converter line up.
The stall test and RPM drops were tested with Stage V transmission, stock turbo with a PPE 350HP tune, stock size tires in our 3500 dually. The example stalls and RPM drops are strictly to help you decide which may be best for your truck. Big tires without gear swaps will raise your brake stall test numbers. We would appreciate your feedback on your trucks’ performance with different gearing/tire and power combinations. If you care to share your results please respond to
[email protected] Use Stall Test Results in the subject line. Thanks for listening.
The SC1050-SC1054converters are 200-400 RPMs less stall than the stock converter, from 02-04 most of the power was made on the top end so with the Allison having tow haul with lockup in 2nd we did not try to tighten the bottom end up much. We spent more time with getting the trans to hold than we did working on the converter.
GM-1055-3D
Approx. brake stall is 2600 RPM
Our 1055-3D converter will let huge turbos spool and light. It allows great turbo spool-up and will couple well as a result of utilizing larger windows that offer the more efficient fluid flow . Our #55 IS NOT intended for towing, but if you insist you can, It has no limits. This was designed for drag/sled pulling trucks with XLarge turbos that need to spool.
GM-1056-3D
Approx. brake stall 2000
This is our journeyman converter that incorporates an OEM style stator and custom modified impeller to allow low end torque multiplication (" gets the load moving") and high end efficiency ("puts the power to the road"). Combined with the Sun Coast triple clutch and billet cover it is a great converter for daily driving, towing and or racing. This converter spools good with stock to medium size turbos.
GM-1057-3D
Approx. brake stall 1800
Our 1057-3D converter established a benchmark for performance torque converters. Often referred to as the “McRat” it has set numerous records at the strip since its’ inception in 2005. Our #57 series incorporates a modified OEM stator and is coupled with the "Velocity Series" impeller. It allows good turbo spool-up with stock size turbos running mild tunes and also offers more efficient fluid coupling than our #56 converter. If you’re running the larger turbos and the wild tunes and need to spool see our #55, #58 or #59 series converters.
GM-1058-3D
Approx. brake stall is 2300 RPM
This converter is great for everyday driving with stock to medium size turbos and big HP tunes. It will brake stall at 2300 RPM, but still couples at cruising speeds. Shifts at 2000-2500 and you will see about a 500 RPM drop. This converter has no limits.
GM-1059-3D
Approx. brake stall is 2000 RPM
Ideal converter for twins or quick spool turbos. Our 1059-3D converter will brake stall about 2000 RPM and couples nicely at wide open speeds. When your shifts are at 2000-2500 cruising you get about a 500 RPM drop with the 1059. This converter has two limits, it requires a minimum tune of 220HP and quick spool turbo.
have ran more than one converter, but I was curious if there's a thread somewhere that talks about the different stall speeds, applications, and opinions ect. of all the different converters. Anything from SC to Precision, to ATS, whatever. Just wondering, since I haven't really been able to find much by searching around. 
