126K? It's just getting broke in
Personally I would just fix the torque converter and the gas tank. My 93 notch has 171K and still runs like a top.
If your gonna rebuild it your gonna need new pistons, rings, bearings, freeze plugs, timing chain, gaskets, valve guides etc. Plus machine work on the block, crank, rods, and heads.
Have someone who knows what they're doing help you assemble it. IMHO I'd rather have a motor with 126K than one that was assembled by someone who didn't know exactly what they were doing, no offense.
-Josh, aka the tireburner