Today I had someone (whose automotive opinion I respect) tell me that early small block chevys did not use a center bolt to retain the harmonic balancer, and in fact their crank snouts were not even tapped to receive a bolt.
Although I did not believe this was true, rather than tell him he should stop smoking crack, I searched the archives here to see what I could find out. And lo and behold I found another reference to this oddity.
Originally Posted by syclone
If they are factory they are 7/16 fine thread but many of them never even had snout bolts so doublecheck your bolts with a gage in case someone has drilled and tapped a different size
So what is the scoop on this ? If GM in fact did not use a crank bolt on the first small blocks, when did they start using them ? And can a non-threaded crank safely be drilled & tapped for a bolt ?
The reason I'm asking is I went to fit a degree wheel to my '64 327 last night and was surprised to find no bolt there. Not only that, but in this case it looks as if there was a bolt at one time, but it was broken off just below the end plane of the crank, and then Einstein the mechanic tried to drill it out with a dull bit which really made a mess of things. (see attachment)
Any useful advice is greatly appreciated.