[BlackSTX]

Funny thing Cody, we had a guy with a similar issue a few weeks ago. Had an new/reman engine done and is now having a similar issue... white smoke. Also says it's runs like a gas engine which is too rich; seems like it loads up at idle, but if he gets it up to speed and hammers on it a bit, it clears up. We're scratching our heads at this too. He insists that the mechanic who tested the compression for him says it's good on all cylinders, however we suspect he may be losing it somewhere accounting for the white smoke, though the timing issue you mention seems like it could also be something to consider.
My understanding is that if you have the compression it should burn, and additional fuel will give you black smoke..... However, if you're injecting fuel past TDC or too late, I imagine it could lead to this condition; that seem correct?

When I worked at a Chevy dealership, we had a local fleet with loads of 6.5L naturally aspirated trucks. They were bringing in an average of 2 trucks a week with knocks, or rods out the side. Most of the trucks were all near 100k and '93-4 models too, if I remember correctly.
One of our truck guys said the 6.5 is a good motor, but most people either lug them or wind them up too high, too often, and it will kill them quick.

I'll check you situation with the owner where I work, he's the one ask, he's worked on them for years. Perhaps with what you have come across it may shed a little more light on the problems both of our customers are having.