When you do put the AC in it, I'd like to know how you did it, and what components you used. Contemplating the same mod myself.
HP wise, I'd use a slightly milder cam and a stroker kit (393) to up the bottom end and mid range torque. The 393 over the 351 is worth nearly 50 ft/lb TQ @ 2000 RPM.
Set the rev limiter at 6000, do routine
oil and plug changes, and the engine should go about 120 - 130k miles before rebuild time.
These Fords just seem to run forever it you take care of them.