2012 isx coolant pressure

[en6x]

I bought this truck two years ago to use hauling grain off the farm. 2012 Pete 386 735,000 isx15 10speed it was fleet maintained rev limiter at 1700 and speed limiter at 64 so I figured I would let the shop delete it while they were taking that stuff off. Yesterday when I got back to the field it was blowing coolant out of the pressure cap so I changed both caps on the expansion tank washed everything off ran a hose from the pressure cap to a jug and took another load to mill which is about 8 miles away it collected two and a half quarts when I got there but didn’t push any more out on the way back home the hottest it got was 185. I haven’t capped off my compressor yet but I’m quite sure it could be a head gasket are there any reputable shops in the Mid Atlantic area that specialize in these engines that you guys know of? I would like to have it done right the first time it’s set at 400hp from the factory but would 600hp internals and hoping to get rawer to tune it. Thanks for the help