My '97 K1500 extra cab (bought new) has a 1-piece drive shaft from the t-case to the diff. The rear U-joint failed and I discovered it has two different size bearing cups? The diff yoke is for 1-1/8" cups and the shaft yoke has 1-1/16" bores. My local parts store didn't list a 2-size u-joint. Is this a standard GM trick or is my truck a special case? Any reason I couldn't just bore out the shaft to accept 1-1/8" cups? The inside snap rings seem to line up ok - the cups are just too big. Thanks for any wisdom on this. - - - Updated - - - Ok, I guess I found an answer. The drive shaft was just made that way. The shaft has a fiberglass tube with aluminum ends. I found this listing on eBay - "Firebird Conversion U-Joint 10 12 bolt 1 1/16" Caps x 1 1/8" Caps". There are several other 2-size combination and conversion u-joints listed as well. May ream out the shaft anyway.