Its an age old answer-it is yours do as you wish...and be happy...
I like Hot rods..they are cool..and there is no investment(By definition of investment) In old truck restoration..added up you will find a huge loss in money...not a gain...in most cases..not all but most...
But hey howard hughes blew big bucks building aircraft and he didnt care...and we enjoy what we do when we build Hot rods or whatever...
I cannot drive a 216 or a 235...i would only end up redlining the engine until it blew up...I cant drive that slow...
I know what i want and what i like..the choice is yours...as it is your money not theirs...
I would advise like others have that if you change the power plant that you also upgrade the safety features...without good modern brakes...you might possibly have an accident and injury/worse can occur..
Eiher way we all look 4ward to progress pics!..
