I currently have a th350 but would eventually like overdrive. I have a slightly built 350. Just a few edlebrock parts and headers in a 1976 G10. I want to road trip in it with very little to no towing.

Here are the options I’ve tossed around:

Keep the th350 and get higher gearing in the rear end.

Swap to 700r4. I’ve seen mentioned that they need a few upgrades to become reliable. How extensive? Am I right in thinking that this would be a drop in swap?

Swap to 4l80e. Probably the best option, but also the most expensive. I think the transmount needs to be relocated, driveshaft shortened, find a suitable wiring harness and computer... I have a line on a unit ($150) that doesn’t have reverse so a rebuild is in order.

I am capable handling installation and any fab work with the exception of a rebuild, but if it’s not necessary, I would rather spend the time and money else where on the van.

Thoughts?