I have a 1993 chevy heavy half with a brand new motor, about 5000 miles on it.lately within the past few weeks it has been hesistating,sputtering under load. Almost like it skips a beat. Took it to the shop and they cant figure it out. Anybody have this happen?

Those symptoms are usually a sign of a bad MAF. They didn't find any error codes at the shop?

Nope. Nothing. They said it all checked out on their machines. Whats MAF?

Mass Air Flow sensor. Usually a very expensive part. That's why it's always good to know for sure before replacing random parts. You can try cleaning it. https://www.youtube.com/watch?v=xQGSkWEC_u4

Ya. My truck doesnt have that. Its a 1993 chevy silverado heavy half with a 5.7 350 motor

It has a MAP

A bad MAP will cause engine surging and fouled out plugs. A bad MAP will usually cause the vehicle to run rich, causing the fouled plugs. Here is a video on how to test it. https://www.youtube.com/watch?v=B8EVhFc5Yqw

Here is a video on things to check. Pretty much all you need to do is pull a spark plug from either side and see if one or both are black. If so, that will indicate that you have a rich fuel issue. If plugs are clean, then you don't have a rich fuel issue nor a bad MAP. https://www.youtube.com/watch?v=TDbRw-xEtyI