Truck gargles after I shut it off.

[mainiac]

I put new head gaskets on a year ago, used Napa Permatorque. Runs fine, no oil in coolant or coolant in the oil. No white smoke at all. It starts right up when I turn the key, cold or hot. It started boiling over after running for about 5-10 minutes.
I put a 16 lb cap on it, and as a backup truck plowing snow last winter, I plowed a whole snow storm with it. About 16 hrs of the engine running without shutting it down. No gliches at all.
Stopped boiling over, but still gurgles after I shut the engine down.
Any ideas?
Thanks

 

[onetonride]

could it have something to do with your thermostat??? or maybe water pump ? just throwing ideas out there.

 

[LCAM-01XA]

16 lbs is way too much for a diesel, stock is 13 lbs and I personally run a 7 lbs cap, with the 7 lbs cap my engine stays runs cooler, takes longer to heat up when overfueling (heavy acceleration), and cools down to normal operating temperatures faster.