A904 Woes.. not working right..

Question for yea all. 4.2 vs. 5.0 vs 3.2 or 3.8 lever? Geez.
I've read soo much and heard pro's n con's for all. Ordered a 5.0 from summit and will have it tomorrow, but now I'm 2nd guessing myself.

Now I got a aftermarket rebuild kit with shift kit.
Opted for the "Heavy Duty" setup with the shift kit.

Little back story on the use of this trans.
It's behind a 318/396 stroker low ccr 9.5'ish :1
Mild cam. With fitech, Built for torque. In my 72 D100 with a 3:23 gear set out back . The truck is just a daily and for looks. Not hauling/ towing or racing.

What lever should I use with my combo??

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If you don't have one, you should invest in a GOOD transmission cooler. The picture of the parts above shows burn marks so that guy was running very hot! Others who've used that 5.0 can chime in on the # of turns.