Any guidance on my 1970 Duster plans

Well it has the right heads and valve gear. Where's the Six Pack? Is T/A cast into the block?
He's got part of the TA puzzle. The block is the other part.

Nice get without a doubt if it was had for 1K. I get the part about not selling it because you are supposed to use it. As a seller of stuff like that and the "story" sold by some buyers to get things, then see the part for sale somewhere else for a bunch more than you let it go. Nice way to burn bridges. :) Good approach, although if it was a complete TA long block, you could definitely fund a LOT of stuff. Guessing it's in the 6K+ range with a TA block. Nice find

If it is a TA block.
A suggestion if you are close to the seller. Get with Barry Washington at The 1970 Hamtramck Registry Home Page
Look here if there for the last six of the vin The 1970 Hamtramck Registry - Found Section - By Year/Plant (1970 -1979)

Give him the VIN on the block, pass side oil pan rail near the block drain plug. If he has any records for the car it came from, still being around, see about getting it back to the original car. He has info on cars that are not listed in the "found" section.
Run that by the seller and give him some proceeds from that potential sale, sale minus your 1K you gave, then split 50/50, you 70 him 30, whatever the legwork to get it back with the original car. Makes it a win for 3 people in that case.