What Do I Have To Do To My Drive Train If I Have Oversized Tires On My 4X4? I Burned My Transmission Out!?

I have 32in Over All Diameter Tires on My 91 Chevy K1500. My Transmission Went Out After Driving On The Highway In Overdrive. Is There Something I Have To Do With The Rear End? I Don't Do a Lot Of Highway Traveling, But I Do A Little Bit Of Highway Once In a While. Transmission Was In Good Shape Before 5 Hours Of The Highway.