my uncle has a rusty but in ok condition 65 thunder bird with a blown origional engine in it, whats it worth?

Impossible to tell. I depends greatly on the condition.

Hemmings Motor News should offer you some idea of the range.

I don’t think its really worth that much. You said its fine but rust. Rust is not fine and depending on the rust it can be worthless as anything but a parts car. Throw in the blown engine that there is no way of knowing if it can be salvaged or not and you don’t have much left. Plus they weren’t all that rare. I’d be around $1-2000 depending on the rust if all the parts are there.

A neighbor of mine bought a 65 T-Bird about 3 or 4 years ago for 6 grand and it was a running/driving car with new paint.
Needed a few things but nothing serious.

A bad engine can be worked around without too much trouble, but rust can be a real killer on a deal.
I agree; maybe in the 1000-1500 range, but the right person at the right time may give 4 times that as it sits.