This is just my opinion--BUT--If you start with a cam you'll just fall into that performance wormhole. It's usually never ending. The trans has a usual life of around 150k--little more/little less. So, if you do a cam, of course you're going to have some fun with it, which causes stress on your trans, which could cause further wear on your rear-end. I myself--actually a lot of us here--have fell into that performance wormhole. If I had your 03, with that amount of miles--I'd get a tune for it. Lots of guys here use
@BlackBearPerf. They'll tweak your transmission for less slip and give you a more of a performance tune, along with tuning that 5.3, throttle response, torque management etc. I think you'd get more enjoyment with less aggravation, along with way less breakage. If you want check out the "Under Construction" threads, or check out my build thread on my 03. I swapped in a cammed 6.0, which led to a blown trans (Needed a performance rebuild) and eventually a blown rear-end. Just trying to give you a friendly heads up, not trying to change your mind. All of us here LOVE build threads, so take my advice with a grain of salt.
My 03 when it was running good. Not so much right now lol.
This was the 1st 6.0.
