Keep a Small block in it or convert to Big Block?

[bagged91]

I just bought(still have to get pics and drag it out) a clean & solid 72' C10 Cheyenne Super, A/C, p/s, p/b, no tilt/tach tonight. The truck originally had a 350 in it but that is now gone. Trans is there as is everything else. My question is, should I go the easy route and just throw another smallblock in it or since I will be pulling it apart for a detailing, should I put a bigblock in it? I have a really rough 72' Burb with a good running & completely original 72' date coded 402/T400 and I have all of the accesories with it too including the A/C stuff. I could do a "correct" bigblock conversion(I even have the high hump floor) but would that take away from the value of the truck? I may eventually resell the truck so I want to take resale value into consideration when I redo it...

Thanks,
Joe