TF 904 Upgrades

Hi:
Im in the process to rebuild my tf904 trans, trying to do it the rigth way but need a lot of advice because dont know a lot on transmissions stuff; so gonna put the engine and car specs and hope to get your help.
74 Plymouth Duster around 3350 pounds
414" small block with ported Edelbrock heads, mech flat tappet cam, 251/259@050, 580-601 lift, Airgap intake, Holley Ultra 850 carb, 11.5-1 compression.
4 linked 9" rear, 4.30 gears, 28" tall tires.
The car is used for weekends and 3 or 4 times a year to the track, shooting for low 11's or high 10's , already using a 3800 stall 9 1/2 converter.
My budget isnt too big but can do some savings to buy as much as possible.
Thanks in advance.
Lots of pics of my 904 in my profile.