i have a 92 club cab auto cummins with a rebuilt a518 tranny. and i wanna in the near future put a twin turbo kit in it. the pdr sage 4 tt kit. so now for the question my tcase is starting to do the clunk of the input shaft that is common on these so now what would i do? i dont mind manuals at all i love em in cars but as for trucks its either for me but i like controlling the shifts so what would be the price for manual vs the auto and which one would be the better of the manual and autos trannys? so any ideas or builds people have down will be appreciated thanks

 

I personally like the stick, but then I am looking for economy and pulling, I have really no use for a hotrod truck. It almost sounds like you want to have more of a hotrod, so I would stay Auto. Personally, unless you need lockup, I would stay with your A518, but if you did need TC lockup, I would change it over to a 47RH, not RE. Here is a thread you may want to read.

http://www.cumminsforum.com/forum/89...rh-thread.html

 

If you're thinking manual trans - application has a lot to do with it. If you do a lot of street racing, city or everyday driving and not a lot of towing, the 5spd is probably best. If you tow lots or heavy, then the 6spd would be the one.
If you're ok with the auto, then the RH is probably easier to swap in due to the computer stuff on the RE. The tq lockup is really nice. Don't be afraid of power issues if you go the auto route. Properly built they can hold as much and more than any of the manuals. But be prepared to spend some cash to get there.
My auto's rock solid and holding up nicely (towing and all) to my minor engine mods. See sig.
I've run them all and always said "I'll never turn down a manual trans, but I'll take a built auto with a shift kit any day of the week"!