Oil pressure

hello, I might be an idiot. I traded for a new cam and lifters a long while ago for my 383. Fired it up and I have a lot of chatter and no oil pressure. It has a lot of oil moving inside the engine. Looks like the guy I traded with sent me ford lifters which are too small for the bore hole. So I'm thinking this is why I have no pressure these are at least a 0.100 of an inch smaller. I do hope mopar lifters give back my pressure.

.100" smaller diameter as you imply would certainly be a problem or are they shorter? Never the less, the wrong lifters can produce your issue. Replace with new correct lifters after you re-lube the cam with break in lube. Install the valve train correctly including shaft orientation. Prime it before you start it to be sure you have oil pressure.