Intermittent Low Idle Death

[bigbrother44]

87 Chevy V20 3/4 T 4x4 pickup with TBI 350 V8 and TH400 tranny.

Intermittently (I hate that word... ) when I put the truck in gear, it dies. It seems like the low idle is so low that when the engine comes under load when I put it in gear, it kills it. This has also happened a couple of times when coming to a stop while driving (there goes the power steering, power brakes...) The engine is a crate Goodwrench long block that now has about 4,000 miles on it. Any thoughts on where to start to fix the problem? Thanks in advance for any help!

[Pontiac1976]

If the motor was set up good when it was first put in then I would say a tune up and look for vaccume leaks. with the miles on the motor.
If the carb cleaned and rebuiled or was at one time after they might not have set it up righ, might need rebuild. then it comes back to you manifold crack again. fix all small problems first .Then see if there is any other problems that have come since the motor was put in new.