Ok here we go I know there will be many different answers, so when I got my truck it was tuned and deleted just don't know which tune.

Now when getting up to 75 if I didn't take my time the check engine light would come on and be for OD 5th and 6th now it doesn't even shift into them.

So the day old question is should I rebuild or get a new built one?

Eventually I would like to increase the hp but probably no more then 700.

If get a pre-built who should I go with?