burning up distributors HELP!!!!

I have been through three rebuilt distributors in my 1991 civic. I installed a used engine from japan about 4000 miles ago. It was a carbureted engine with the carburetor facing the firewall, my old one had carburation on top. Anybody have any ideas why I'm eating distributors. The last one melted the cap where the coil why goes in

Thanks for the help

First off, most rebuilds are crap. Buy a new sub assembly and save yourself the grief. Usually a cap melted at the coil is from a bad connection at the coil pin, either a botched install or a crap aftermarket cap.