So I'm new to these LS motors. I've got a '04 LM7 in a silverado that needs heads. If I bump compression from 9.5 to 10:1, will I have to re-tune the computer? If I add a small cam like the Crane Powermax LS cam, with 200/208 on a 115LSA, will that require a tune? I need the truck to be a DD, able to tow and get good MPG with stock converter and 3.42s.

Is it possible to do ANY head/cam changes to a LS motor without it running like crap with the stock tune? The closest tuner to me is in Greenville or Charleston SC, both several hours away. From reading here, I see that some guys do their own tuning, some buy "canned tunes", some physically bring their truck somewhere and other send datalogs of their truck to a tuner and get a tune back. What would be best for my situation? Thnx!

 

Holy baby cam batman. Not worth your time. I would suggest a mail order tune from one of the sponsors. It should be done on stock motors let alone a modified truck. You seem like a perfect candidate for a 212/218 low lift 112LSA. You will need new pushrods if you are milling the heads anyways. That should net you 50-70rwhp+ and only cost you maybe 1mpg while maintaining driveability.

 

I know, baby cam that won't sacrifice low-end or idle quality. I'd rather err on the small side because I don't need it to stall or creep in gear. The stock cam is 190 degrees duration, I figured 10* more would not move the powerband much and I could take advantage of more compression. How much cam can be used in 5.3L with 9.5-10:1 with PB/stock converter/3.42s?

I just did some reading on the blackbear site about tuning. Thanks!

 

a stock engine gains from a custom tune, so yes i would get one

 

You can run up to a 212/218 low lift with out hurting low end. But I would dump those 3.42 especially for towing.

Personally for an everyday DD I would run 3.73's

At times I wish I had 4.10's until I get past 70 MPH

I have 3 trucks and I absolutely hate the 3.42's especially for towing.

 

What is your location?
You can find a few other tuners in the state

 

I'm in western SC, about 30 minutes east of Augusta Ga. I bought the truck new, and it's box stock except for a mild shift kit and Z-pack clutches in the tranny.

 

You seem like a smart dude. That 200/208 will be perfect for what you're wanting. Avoid the temptation to go any bigger.