hi everyone new to this site !!! ok so im thinking about getting a 2003 silverado ext cab with a 5.3l the truck has a 228-230 comp cam with 3200 stall hooker headers and built trans with shift kit i was wanting to know how bad this truck would be on gas? and is there anything i can do with the stall like maybe getting away with running a smaller one st help a little with gas ? if so what stall should i get ? i know when getting a truck like this not to expect 20mpg but id like to get the best i can get, thanks !!

 

IMHO, Id run a little more stall or less cam on a performance standpoint. I had a 5.3 with a 222/230 and a yank st3500. It really needed around a 3800 in my opinion. Id prlly run a 4k with that cam, but maybe a sponser could give some better advice.

 

thanks for the reply, how was your 5.3 on gas? im really looking for something thats able to be drivin daily

 

Mine did 15.7 highway the last time I checked it, but the roads around here are like climbing mount everest. I also drive pretty aggressively. I would say my setup could have pulled a solid 17.5mpg or 18mpg under normal conditions and driving. Might sound rough, but those are real world expectations.

Mods when checked:

2003 5.3/4l60 4300lbs with driver
4.11s
longtubes and ory
yank st3500
comp 222/230 113+1
hptuners tune by me

 

thats really not bad at all, maybe even with a good tune i could get a little better mpg being all the roads here are pretty flat

 

buy one that's not modified. You'll be better of for it.

 

My excab usually gets 19-20 on the highway with the mods in my sig. You will probably be a bit closer to what Kelsey was guessing. I would also say run a smaller cam if you want better economy, but to keep the performance.

 

Yea smaller cam (212-218ish) and that stall will be fine if you can baby it. If the tune is dialed in it it should still get high teens.
mine gets 20+ on long trips but only about 13-17 on daily commute with a bunch of idiot drivers on the interstate.