According to the instruction sheets for the Bouchillon Performance kit # BPE 5251:
The long spacer is 2.105" long
The short spacer is 1.210" long
Some hardware stores carry 3/8" spacers. I would think that you would be able to go to a hardware store (Like a local Ace) and buy 3/8" spacers in 2" and 1.25" and get them to work. The long bolt for the alternator that the spacers go on is also 3/8" x 16 x 5" length.
Some of the hardware stores also carry the "generic" 3/8" spacers in chrome plated, but some keep them in the back and you have to ask.