Hey guys, I need a little advice, I have a '99 GMC Sierra 4.8L RC. 4L60E Tranny. Im going one of two ways, need opinions...

The first option is to upgrade the 4.8... I was thinking...

Adding the GM Hotcam (219/228 .525/.525 112)
LS6 springs
Nelson Tune
Trailblazer Stall
K&N Cold Air Intake
and Headers
Dual 2 Chamber Flowmasters (already on truck)
Pretty sure I have the 3.42s out back (stock)

What do you guys think of this setup, what kind of performance am I looking at?

Ok...the other option....

Going with the 6.0 swap, the 6.0 I am looking at already has a cam, and vette heads, maybe a few other internals, not sure yet... But if I go with the 6.0 setup, I am worried about the 4L60 holding up... Will the 4L60 bolt up to the 6.0 if I had to use it temporarily.. How long will the 4L60 last against the 6 Liter? What about the 4L80 swap? My buddies have a fab shop, so I think we can take care of the mounting issues, but I would like to know what I will be getting in to before I do it... and I know I need the adapter harness. What else specific to the 99 Sierra?

 

I think the 4L60e is good up to about 400HP but it also has a lot to do with your particular style of driving. The 1st option will provide you with a truck that's right much fun to drive around but the 2nd will result in a truck that's a WHOLE LOT of fun to drive around!