I bought a 2000 Silverado RC Shortbed with the 5.3 and only 28,000 miles on it. Since I bought it I have added a Borla exhaust, Superchips programmer, and a K&N air filter. I want to modify it more, here are some of my suggestions, but I would appreciate your input.

Gibson headers (Coming soon)
Volant cold air intake
SLP 1.85 rockers
Electonic fans
ASP underdrive pulleys

 

sounds good to me, have fun!!!

 

Everything sounds good in this list except the Gibson headers. They aren't worth a crap. Just save your money and for some mid/long tube headers.

 

Ya ... get some real headers and don't mess around with the shorties.

 

Custom tune from either Wester's or Nelson's. Post up about how well the rockers work for you

 

I'd do a cam over the rockers.

 

long tubes for sure, i have the same truck as you and i think it will move way better with long tubes, oh have you considered doing a cam swap?

 

The ASP UP is worth 8-9rwhp on dyno, and removing the stock fan is worth 4-5rwhp.I would go with long tubes!