Yes you did screw up. You should have matched the gaskets that were in there. The gears should only have .003" hosuing clearance.
Unfortunately the only gasket on this pump when I took her apart was a homemade one. And just one, pump body to the 1/16" steel plate. Looked like Stevie Wonder made it in second grade.
And no gasket at all for the steel plate out to the cast iron cover plate. I've never seen an IHC oil pump like this one before----and no Google results with the casting/IH number on it. Hmmmmm.....
