you just expect to throw on some heads and it run??? You gotta get it tuned man...

converter...

gears......

 

Oooh sell me the 243s

 

on an otherwise pretty much stock 4.8 you arent doing any good... My heads are stock on my truck just as TONS of others are and look at our results, its all about your combo.

You need more supporting mods and tuning before you can honestly take advantage of good heads.

I'll go ahead and get in line to take them off your hands LOL.

 

while you have the truck heads on take the other heads and have them milled. put em back on when theyre done and get a live or dyno tune. i'll bet it'll help you out quite a bit.

 

I don't think your true duals are helping any either. What size exhaust TD's are you running. On a 4.8 N/A there is no reason at all for TD's, and that will kill power down low. I personally wouldn't even run TD's on a 5.3 N/A unless I was runnin major cam. A single 3" exhaust would be plenty for you.

You're running 3.42's and have combo'd your setup with cam, shorties and exhaust to run in the higher RPM's. Add to the fact that the 4.8's lack low end grunt to start with.

You also need a tune.

 

Hey just for all the people who said i need to get it tuned well it was nelson tuned about 3 days ago. So that run is with a nelson tune. Just letting you guys know. But im gunna go get those heads milled or something converter or gears which ever i think will help best.

 

I got my truck tuned once too...

You have to get it dialed in for the EXACT mods you will be running... one tune will "work" with a different set of heads most likely (since they are stock castings) but to make it run the way it should and fuel properly for the airflow differences you need it tuned with the combo you are going to be using... but hey... what do I know...