I've got a 6.0 with 219/228 .555" lift on 112 seperation, 44lb injectors, still has cats but no restriction past that, 4l80e in a 2003 gmc 2500hd 4wd with 4.11 gears. can strip it down to 6,000 lbs. e-fans, cai.... Anyone with something close to this? I would like to know what to expect to the rear wheels and in the quarter. also any suggestions on next mods. how much horsepower can you get out of a tune on this setup?

 

all depends on the money you wanna spend... ull notice alot with the tune tho, it will make ur cam come alive, and also will work well with the rest of the supporting mods, my personal prefrance would be a stall, and depending how crazy u wanted to do go boost? but if not a stall, under drive pully, heads, ? just my 2 cents

 

Well I got 20 horsepower out of my near stock 5.3 on a 91 tune. I would say 30 hp would be close if its never been tuned. If I had to guess I would say your making around 300-320 at the wheels, and mid to high 14 sec passes should be obtainable depending on elevation. These are just my estimates, take it to a dyno or track and get some solid info!

Throw on some headers if you don't already have them, and a Torque Converter. That should drop your times considerably.

Hopefully someone will chime in with a similar combo and give you some of their numbers.

 

taking in to a dyno to tune it if the guy would ever call me back. Until then keep tinkering under my shade tree. Have some 317 heads i might have milled and ported what will that be worth for hp and torque gains?

 

I've never seen a graph for aftermarket heads, but I would say 10-20 hp if you already had all the supporting mods. I wouldn't get heads unless you have a cam that flows more then stock heads can handle otherwise its kinda poinless.

The stock heads flow well, and you can make great power with them. I would spend my money toward a supercharger or turbo, then you can force the air through the heads!