Topic: 22r standard to auto swap

[hensonshome]

I have an 85 4x4 SCPU with the 22r that I have lifted 4", added 35x12.5x15 boggers, changed r&p to 5.71's and converted steering to an orbital and hyd. ram set up. The setup has worked good for me with mostly muddin and some light rock crawling.
In 05 I went head first off a roof here at home one morning and changed my life to a quadriplegic with only arm and very little hand function. I can't drive a standard now so the only wheelin I've done since was as  a passenger and as anyone can imagine is not near as fun.
I have since pulled motor and transmission to rebuild the tired 22r and then decided to convert to a simple sbc and t350/205 combo.  I've already purchased the setup. I had planned on to rebuild the combo before install.
Now I'm having 2nd thoughts because I'd have to no doubt change the r&p's to 5.29's because the 5.71's probably can't handle the added hp. Then also with all the other mods required with stuffing all that in such a small hole. I'm not scared of it, just kinda decided to explore a different option.
All that book to ask this question. What is the best auto trans/tc option for simplicity and reliability for strictly off-road use? Any info and advice will be greatly appreciated.

[a1gemmel]

For a chevy motor, for my money either a TH350 or TH400 has got to be the ticket. I'd consider putting an NP231 behind it instead of the 205 to get a better low range.
To flip your question around - you're concerned about reliability with injecting a bunch more horsepower. Have you considered using a chevy 4.3 instead of the V8? It'll package easier and hit the sweet spot of being more horsepower than the 22r while keeping it at a reasonable level.

[hensonshome [OP]]

I left out the main topic in my question. I was wanting to try to stay with the 22r and use an automatic behind it.
I haven't considered the 4.3 but I do know they are very reliable

[Snowtoy]

If you go the 22r route, you wont need to change out the 5.71's. 

With the 4spd auto the truck will have less power than it did with the manual as it was over geared with the 5.71's, and with the auto it would be about stock performance.