I have a 5.3l truck and it has dual flows, intake,power programmer, and pulleys. My problem is that in the summertime i ran a 14.8, and that was without the pulleys. Yesterday i ran steady 15.1 with pulleys. Why is this happening?

 

Welcome, that is weird. It should be the other way around for reasons. You now have a pulley and its colder.

 

it could be the way you launched your truck. I was foot breaking mine up to the point to where the tires would almost want to spin. crappy 60' times and crappy et. I now foot break at around 1000 to 1200 rpm's. better 60's and better et.

 

hey allmtr check your shift points and see if they went down any. after putting on the pullies i seemed to be shifting from 100 to 200 rpm's sooner.