To DO or NOT TO DO??

[painterljp]

We have a 1971 Chey Shortbed. It is all stock 307, 3 on tree. No power nothing brakes or steering. Runs fine. All original factory stuff. Looking for opinions, we may want to put a 327 already built with roller rockers tall valve covers, cam, etc. Lots of goodies. To put in truck. But that is going to destroy the all original stuff. But add power steering power brake upgrade. And an automatic. Take body from frame and just freshen it up with new paint and what ever bushings and such it needs. It is a New Mexico original truck so has no rust. PO was a school teacher and got the shop.class to paint it white and removed all trim, just lower. So we're putting all that back to stock. Need some opinions on whether to put 327 in it or leave 307 in it?? On tree or automatic. Just feels like no power and not such a joy to drive. What do you all think??