carsnstuff

So I have an engine that I built that I am getting ready to swap into my 2000 Silverado. the current engine is the stock 5.3L. The engine I am putting is a 5.3L block that has been bored out to 5.7L, Texas speed stage 1 cam with .550 Lift, and 799 heads. I do plan on getting it tuned, but wondering if after I do the swap it will run on the stock tune, and how bad will it run if it does. I would to prefer to run it stock for the first 500 miles or so just for break in, and then get it tuned.

G Atsma

You are going to need a tune right away. Too many changes to your airflow. It will not know how to run, basically

carsnstuff

That is what I thought people might say. Let me ask this then, should I even try to start it without having some kind of work done on the pcm. Or can they get some kind of base map just based on my specs?

G Atsma

You might look around to see if someone might have a similar combo as yours, which is actually fairly common. It will likely start, but not run very well.

2xLS1

iTrader: (25)

It will run OK on the stock tune as long as you didn't change the injector size. The MAF will register the additional airflow and the fuel trims will adjust to keep the A/F at stoich in closed loop. Stock truck tunes are pretty rich in PE mode. If you have any issues at all it might be too low of an idle speed but the Stage 1 cam is really small.

Rider_01

I didn't know the stock tunes were that rich. I am guessing they did that for safety.

2xLS1

iTrader: (25)

And 87 octane fuel. GM tunes trucks different than performance cars.