No question the finned cast aluminum deep pan is the way to go. Better fluid cooling and a great way to stiffen up the case. I purchased a no name cast finned pan on Ebay for less than 100 bucks.   That's what my trans builder got for me. Looks just like the TCI piece, but has no name cast into it.
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
| 
