Intermitten tranny.... Any suggestions?

I took a trip to montana from seattle WA. About 400 miles into the journey, the tranny on my 83 GMC blazer acts up. First OD goes, then about 30 miles later, all the gears go. If i let it sit for 10 to 15 minutes, it will drive just fine, untill i stop again.... Then when i attempt to accelerate, it slips and goes nowhere (affecting all gears). I did the sit 10 to 15 minute speal multiple times to limp it home. All the fluids are correct in amount and specifications. I've heard it could be the vacuum hose or also even the cruise control. PLEASE HELP!!