I have a '60-70s chevy 350 and on the balancer the timing mark isn't in line with the keyway on the hub. I thought it had slipped until I read somewhere that for these years of chevy 350's they are 10 degrees off. So when I time it with the indictator on the timing cover, am I susposed to add 10 degrees to it or do it by the mark on the balancer?

Or anyone know why it is 10 deg. off?


Here's some info on one of them w/ this 10 deg. thing:

6272221 - 6.75" Torsional Damper
This cast iron torsional damper (harmonic balancer) is used on most 1969 and later production 305 and 350ci small-block V8s. It is recommended for V6/90º racing engines and V8 applications with limited clearance. 6.75" diameter balancers have also been used successfully on drag racing small-blocks in classes which permit the use of cast iron dampers. The timing mark is 10º before keyway center line.

 

It wasn't just 350's. Timing tabs were either bolted in the traditional place or welded to the timing cover, requiring you time it from the top. California engines had this welded tab. Obviously the balancer must match the tab type.

I always check it at TDC to verify the mark is in the right place. If it isn't, I mark it in the correct place.

 

You should degree the engine, then you would know for sure where you are at. If you can not do that, the least you can do is make sure that you have the correct timing tab for the harmonic balancer being used. Some of the early timing chain covers had them welded on and later tabs are companion bolted with the cover.