I just over heated my engine climbing a hill
pulled over and saw the trans fluid boiling in the res. I was thinking of changing collant , trans fluid and eng oil. Any help would be appreciated.

Its a 1999 winnebago adventurer 34v diesel
allison mt 643 4 spd
was also woundering if any one knows the capacity of oil , trans fluid, and coolant

If you saw transmission fluid in the coolant reservoir that could mean a leak in your transmission cooler. I had that problem in my Allison MH3000 and according to Allison it means an automatic transmission rebuild if the coolant got into the transmission. The ethylene glycol in the coolant eats rubber seals and clutch material over time. Hope that helps, even though it may be bad news.