My 81 has the GM151 with the SR4 and I know the trans won't last long. I've done some searching on replacments and it looks like a T4/T5 would be a bolt in conversion. I also know these trans are questionable also. Call me crazy but I plan on keeping the 151 for a few differant reasons one inclueds puting on FI. Ok now for my questions:

1. Is the T4/T5 really a bolt on conversion with my D300 (no adapters) ?

2. Will they hold up to 151's in heavy off road use?

3. Are there any other trans. that will bolt to my bell housing & tcase? (w or w/o minor mods)

4. What would you recommend to swap in?

Keep in mind I'm trying to keep this low budget and would like to stay away from the $$ of adaptors but I know sometimes you don't have a choice. This will also be a stricly off road Jeep and will only run 31x15.50x15's.I may need to run the SR4 to begin with but I just want to start keeping my eyes open for a replacment. So any and all comments and suggestions are welcome. Thanks in advance and also for making this such a great place!