i googled a little bit and found this info for a 2001 s-10
Cargo area dimensions: length (mm): 2,256, front width (mm): 1,394 and width between arches (mm): 1,024
1,024mm is 40.31 inches...i went out and measured again and it is 1 cm under 40 inches so i think it will work out, the handle on the lower box would go in first to clear the wheel wells