I was gonna say why not ATI? The local guy that builds my converters and transmissions has a very close relationship w/ ATI and uses a lot of their parts.
Atlantic Coast Converters in Conway, SC, is who I use. Almost everyone around this part of SC and NC uses them.


CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax