Vortec 350/ Black box

[99TransAmls16spd]

Is it worth changing the factory tune on this PCM? I have a '98 Z71, almost entirely stock with the exception of dual exhaust (factory 2 into 1 muffler removed for 2 mufflers), a descreen MAF, and removed airbox. I manage 16.5-17.5 mpg on pure highway runs and summer grade gas, but mix driving, at least in the winter is horrible at 13-14mpg.

I know the 411 swap is common, and fairly simple - but is it worth it in my case (truck will not be modded beyond what it has been other than maybe the throttle blase). Or will sticking with the black box pcm get me by - and is it worth spending the license on?

Thank you

[LS1_Dragster]

Yes, absolutely, my 97 runs so much better and smoother. The transmission shifts far better too.

Lee

[99TransAmls16spd]

Out of curiousity, did you use the base tune from the '01-'02 Express van, or did you modify it?

[Aloicious]

Out of curiousity, did you use the base tune from the '01-'02 Express van, or did you modify it?

if you do your own tuning, the PCM swap is by far the best thing you can do for the truck. I love mine, the 411 and efilive are the best mod I've done yet. if you aren't going to do your own tuning, then the gains are negligable. the main gain from the 411 is the vast amount of control you'll get vs. the blackbox.

since you mentioned spending a liscense, I'll assume you plan on doing your own tuning, and I would highly recommend it.

[LS1_Dragster]

Out of curiousity, did you use the base tune from the '01-'02 Express van, or did you modify it?

I modified it, stock tune wouldnt run very well since I had engine mods done.

Lee

[chevy052500hd]

change to the 411, my truck shifts so much better, and plus I can access the lean cruise stuff to help with gas mileage.