Opinions please.

I have a 74 Ralley (real ralley car) originally w/ 318 auto air.
I do NOT have the original motor.
This car is a super clean California car.. fully restored.
Question is this...
Should I go thru a 1971 318 that I have to put in it..
OR , Should I install a 440 that I have ?

What would do better on resale when that time comes ?