2.6 engine options

[recian]

My truck is a 86. It's got 26k original miles and it's in great shape. Only has one tiny rust hole in the bed the size of a dime. I can't find any other first gen trucks for sale in my area. I could drop 2k on a new engine and probably another 500 on a fuel system repairs due to sitting but with none for sale I don't have a price point to know if it's worth saving. It's very unique because it's probably the lowest mileage 1st gen d50 I existence. I'm finding engine internals. Specifically the crankshaft for sale now. Rockauto even lists a crank but one is FWD other has no description. I know fwd block is different are internals interchangeable?