Without going to an overdrive trans, any of the SM465 or SM420 combos with the 350 are good to go. The SM420 has a lower first gear, granny style, like the stock M715 trans...some like that...the SM465 is a little newer and therefore may not be as used as the SM420...some like that...ratios are:
SM420 1st(7.05) 2nd(3.58) 3rd(1.71) 4th(1.00)
SM465 1st(6.55) 2nd(3.58) 3rd(1.57) 4th(1.00)
I dont know applications offhand but those are things to look for.
Lord send your Holy Ghost into our hearts and make the desire of our hearts Your Will.
Pro-choice, that's a LIE, babies don't choose to die!!