Slant Six 170 vs. 225

I’ll defer to the guys that build these every time, I only drove pretty much stock stuff, but….
An engine that felt sluggish 39 years ago with 145K (100hp- new rating?)
Vs
An engine with 1500 miles and 145hp.

of course this all depends on how accurate those power numbers are (or were), but the question being; would you feel 45 hp, I would say…You’re damn skippy your gonna feel 45hp, thats almost 50% more. Would you feel 45 hp if you were at 500 hp, probably not. I’d even wager to say that at 500, you’d be hard pressed to notice a 50% increase (unless of course you were racing) but at that point you’d be so far over what a 63 dart needs to drive around, that you’d never be making use of what you had already.
BUT, points to ponder;
1) originality
2) “a little more pep. (I'm not trying to turn it into a muscle car).”
3) how much do you want to spend for that little more pep & how much will you get comparing dollar for dollar what you will spend on those 2 alternatives?