I bought a used 98 motor it has a stage 3 cam and new lifters the cam has less than 200 miles on it. the motor in my truck is running good oil pressure strong i know the cammed motor runs good but i dont know how it was maintained before me. Would it be a better idea to swap the cammed motor into my truck as it is or tear my good motor down in my truck and put the cam in that motor along with new head gasket valve cover gasket?

 

I'd run the other and keep a spare. But thats me.

 

Run the motor that already has the cam in it?

 

Yep. Then if it does take a dive you have known good motor.

 

When you recam a motor dont you break-in the cam to ((match the motor)).maybe uam wrong but i wouldnt think it would be good on the cam to swap it in a different motor and have to break it in again. Iam new to major internals of a motor just want to learn

 

Bring the lifters over to the other motor if necessary...

 

Well i tore down the cammed motor due to leaking oil from the timing cover and the guy that had the motor before me never sealed things properly and leaked oil so once i pulled the head the 6th cylinder piston was badly pitted so the cam and everything is going into my good motor along with a new head gasket and everything

 

Yes.
Yes. If swapping the cam, be sure to swap the lifters that were used with that cam in exactly the order they came out of the old motor. Cams n lifters develop a "wear pattern" between them.