Where can I buy a reliable remanufactured 318 for 1971 Duster?

No worry on me giving up the hobby. I’m pretty much married to this car. I bought it when I was 19, dated my wife in that car, and she fully supports us keeping the car up. I was close to having someone not too far from here do a restoration - but the cost came in about $15K over my threshold of pain. I’ll go back to plan A and have things done piecemeal. I spent some time today experimenting with a new sending unit and fuel gauge and I’m now pulling the instrument cluster out to replace the gauge. I’ll touch base with the guys in Lake City. That’s only 4 hours away.
We lost a good machinist and mopar specific machine shop whe Dan Dvorak passed away a few years ago. He was located mid state in Waldo, so it was inconvenient for all, but worth the trip. Luckily I had kids going to college in Gainesville, so it was always a good excuse to see them too.
I am getting ready to head up north (vermont) for the summer, but if you have not done anything by the fall, I will be glad to help.
Make sure your sending unit has the grounding strap that jumps over the rubber hoses to the steel fuel lines