Well heres the thinker:

The first pump I blew was the newer style pump which I have never seen have a spacer. The 2nd pump I blew was an older style pump. Maybe the 1st one blew from old age and the 2nd one blew because it was supposed to have a spacer? I've never seen a spacer on a pump, but I have also never seen an older style pump installed. Maybe only the older ones come with spacers??

-SCerb

http://www.scerbfab.com/carb_faq.html