Starter Motor and shims
 

How do I know if I need to use shims when installing the starter motor on my '68 327?

Vic

With the starter bolted in place, you should be able to just slip a straightened paper clip between the tip of a bendix gear tooth and the tooth valley of the flywheel. I've seen other instructions say to use an 1/8" drill bit between the starter shaft and the tip of the flywheel gear. That way puzzles me, as my bendix gear at the thinnest point is a lot thicker than 1/8", meaning that way isn't going to clear. If it checks out to be too tight of a fit, put a shim under both bolt mounting bolt points. If too loose, only shim the outer point to rock the starter closer and tighter. If the mesh is wrong either way, you'll hear it grind when you go to start the engine.

Thanks Chuck. Just so I am clear..
With the bendex gear extended to mesh with the fly wheel, you want the highest point on the bendex gear tooth to be about 1/32" away from the lowest point on the flywheel tooth valley. (1/32" being the diamater the paper clip).

Is that correct?

Right. Then let your ear be your guide after that. Too loose of a mesh will sound more like a sawing grinding noise. And if too tight, the bendix gear may not kick back away from the flywheel, or not mesh at all.

there should be 5/16 of an inch between the outside edge of the flexplate/flywheel teeth and the shaft of the starter.
use a feeler gauge set.

the 69 350 in my 71 chevelle was not milled properly from gm?? and i have to have all starters for it milled down 3/32nds in order to function properly.
took me 3 flexplates and 6 starters in 3 yrs to figure it out!!
i was told by an old gm tech. that they had alot of issues like this with the 66-72 engine blocks back in the day but usually the other extent, milled to much requireing 1/8 inch worth of shims to get the desired 5/16 gap.
a stock starter mounted to my 69 350 with no shims measures 3/8 to 7/16 from teeth to starter shaft!