I had a '96 Cummins auto, that's why I have my '01 six speed. Go mild on the upgrades, 300 hp should be about all a virtually stock transmission will live with.

Start here:

http://www.tstproducts.com/tstpowerkitwithoutvideowithkdpkit.aspx

Add a Transgo TFOD-HD2 shift kit and a tighter converter and call it good.

Give Mark at TST a call, he'll walk you through it all.

Robert

'68 Fury Convertible
'69 300 Convertible
'15 Durango 5.7 Hemi
'16 300 S Hemi