My 98 ram 2500 5.9 gas dies when I put it into gear anybody know what that could be.
I'm thinking torque converter? Brand new engine

 

New engine? Check the crank position sensor. They are frequently victims of such a swap.

 

I have already ran it I got 463 miles on it. Just went out there an started the the truck.everything put it in drive an it dies instantly. Everything seemed fine when I drove it home prior to this

 

If you put it in N does it still die? Or just D? How about R? Does the truck try to lurch?

 

It does not do it in neutral it keeps am idle just fine.
it does in both R n D an does try to lurch but dies

 

Not sure if they have an electronic TCC but if they do you may be able to break it free with a few neutral drops...ya, it sounds like a locked torque converter. Try jacking the rear end up and toss it in gear.

 

Well dropping it in neutral a few times didn't change anything

 

98 should be a 46re, they definitely have electronic OD and TCC. There should be a relay under the hood, or just unplug the entire electrical connector at the transmission and see if it's still locked up.

 

I'd go for the plug, myself. It takes everything out of the circuit, including wiring faults. It won't make any difference if the clutch is locked up tight, but if it's being commanded to engage the clutch this test will show it.

 

Try the basic stuff first. Can you get it to stay running if you feather the throttle as soon as you put it in gear? Was the old iac used on the new motor? Do you know if it's getting good fuel pressure? Do you have any codes?