u joints are common sizes, you need to take it to NAPA and let them measure the outer diameter of the cups and the length, go to a good parts store like NAPA , advance cant help if its not in the computer and trust me , your front axle will not come up in the computer for that van.
2004 Ford E250 5.4 4r75w dana 60 with 3.73;'s (Current)
1992 Dodge B350 360/46rh non lockup /9.25 rear with 3.90 cogs (sold)
1986 GMC Vandura 2500 305/TH350/3.08 rear (Sold)
1994 G20 Ex Virginia DOT crew van 305/4l60/3.42 G80 10 bolt (Sold)
1969 Chevy G20 Sport van 230,3 on the tree, 12 bolt with 4.11 cogs.(Sold)
2004 Chevy Express 2500 4.8,4l80E,3.73 (sold)
1990 ford e250 club wagon 460.E4OD,dana 60 rear 4.11's (sold)