i have a 97 f150 4.2 with a recent rebuild now its burning 5 qts of oil every 1000 miles should i rebuild again or buy a new motor

 

That would depend on why it is burning oil. Is it valves or blow by? When it was rebuilt, was it a re-ring or did you bore the cylinders and replace the pistons.

How old is the rebuild and who did the machine work if any? Was the machinist reputable or just some guy down the street? If it was a re-ring vs new piston job, the hone job could be bad/overdone...

Do some compression tests to see whether you have a valve issue or a ring/piston issue...

 

engine may or may not be the problem....are you sure it's not leaking oil somewhere and burning off before it hits the ground ??

I also agree a compression test will tell you a lot.