How to Assemble the Front of a Small Block

Oldmanmopar said
The bolt with the hole in it was only used on early motors and did not have the dripper then. The dripper was a more effectiv oiling method used on later motors and got its oil from the oil run off or overflow from the front cam bearing. The combination of the two is a good Idea and I have done this. But it is not nessasary. I have factory bolts like this and can also make them from Grade #8 bolts in the lathe if needed .Steve

How early I wonder, as the above pictured 1971 318 and the industrial 1965 poly 318 I tore apart, had no hollow cam bolt, or a drip tab, just four regular cam retainer bolts. Maybe 273s were different, or it was a hit and miss thing from the factory?