The guy from your work has probably got some facts confused. Anyway, no such animal as a four bolt 283. The four bolt SBC blocks were designed for engines that produced relatively high torque and HP. Therefore not necessary in a 283. hahaha
All kidding aside, as designed, the little mouse motors weren't prone to twisting the block and pukin' the crankshafts out. So, four bolt caps weren't really necessary.
