4-bolt main. Unfortunately it’s completely fucked. Needs rod bearings, main bearings, a crankshaft, and cam bearings. So that’s a couple hundred dollars and my buddy can’t let me keep the engine in his garage that long so it’s a moot point anyhow. Going to contact the guy I bought it from and see if he’ll be nice. Certainly didn’t seem like he’d be hurting for the $300 I spent on this.