be sure to watch the engagement of the converter snout in the crankshaft. If the converter was spec'd out for 1/8th inch plate, the snout would be extended for proper engagement. If it doesn't seem to go in very far, your going to run into pump problems because the bolts wont hold converter centered enough.
this is a reason i like transmission specialties converters, they make the snout screw on/off so you can use the same converter for different mid plate thickness.