I have a 2006 4.8 rbsc tuned, intake, 4.11 gears, corvette servo, longtube headers, 3 inch Y pipe with dynomax bullet exhaust. Next I'm going to put a 228/228 cam and a 3600 stall. Any other suggestions on more mods I can put on my truck? Also I know I'm going to have to rebuild my transmission. I'm planning on putting a transmission cooler and red clutches.

 

Being in your shoes previously, I'm gonna say pull the 4.8 and find a 6.0. You can sell the 4.8 and have about as much in what a cam kit cost into the 6.0
In my ext cab I had a 224 cammed 4.8 and swapped in a stock lq4 and the stock lq4 was .7 faster due to the torque

 

I would suggest a different cam. That 4.8 and the 706/853 heads don't agree very well with the 228r. Something like a 222/226 will be miles ahead. Otherwise get a 6.0 as suggested.

 

Depending on your goals.. I went turbo, pretty simple install decent price. If wasn't very impressed with the last 6.0L I drove, but with your other mods and a stall it might be alright.