I was wanting to also add a lower pulley with my chip or reflash. What size is safe, without having to worry or is that just part of modding.

 

everyone has there own opinion on what safe is. Personally i think for long term longtivity of the motor/blower/tranny a 4lb is the most but people will all have there opinions on what is best. Do what you feel safe doing and as long as your happy thats all that counts.

 

I agree with LR2.

I went from from a 4# to a 5# and didn't see much gain. I think once you go above a 4# pulley that your returns start dropping fast.

The gains are linear for every 2#'s of extra boost until you go past a 4# pulley. You get half as much gain going from a 4# to a 6# as you get going from stock to 2#'s or 2#'s to 4#'s.

These are hard numbers recorded by High Roller when he dynoed every mod one at a time.

I think above a 4# pulley is when the Eaton really starts to drop in efficiency becauce all gains are linear up to that point.

 

I bought my truck in nov of 02. It had 6000 miles. I imediately put on a 6# pulley and a diablo flip chip. i had one program burned fairly conservativly for the street. The other I had burned for 104 octane. i now have 27,000 miles on my truck, and i've never had a problem. I dont know about the gain differences, but i do know that when i combined the 6# with the chip it really woke the truck up.

 

I'll 2nd that and I only put on a 4#er and a chip. (I can't imagine a 6#er) Do what you want. When I first got the Lightning I said I'd keep the truck stock. Then I was debating over a 2-4# pulley. I never really put much thought into the 5-6#er cause I wanted to be real conservative. I went with the 4# lower and was real happy! But sence the 4# lower I also went smaller upper. (I could have just boughten a 5 or 6# lower...)
Not sure if I'm helping you any. One second I told ya 4#er then the other I'm saying go for the 6. If I had to do it again, I'd pry stick with what I did at first. You have to start somewhere. A 4# lower and a chip is a great way to start. Good luck, Shane