318 vs. Slant value

Got my 73 swinger that was my grandmas. Dad always said it was all original and it had 73k miles on it. Body needed quarters etc but the slant is cancer to drive!

I found the owners manual and it said 0-60 in 17.5 seconds and holy hell i live in the mountains and trying to go up a hill it struggles so im having a 360 put in.

I somehow doubt anyone would pay me more for the slant even though i have the original bill of sale than they would for the upgraded 360 and 8 3/4 sg rear.

The person wanting it would have to be eccentric as hell or just want it to sit around imo.