Sorry if I doubt this one AD, but I’ve heard the discussion before. The only way to get more torque out of the AD starter would be to add an extra set of coils. The only way to do this is to change the case to a longer case like that used in the early Oldsmobile for instance. Other wise there isn’t room for the extra coils.
I bought a set of what was supposed to be “High Torque” coils from a generator rebuilders just to make the comparison in a couple of 216 starters that I had on the bench for rebuilding. There was none! The coil wire cross section was exactly the same as the stock coil and the measured resistance using a high precision HP laboratory grade LCR milliohm meter that will read very low resistance gave me the same reading as the stock coil.
I would suspect that the difference that you noticed is the difference between an old starter and one that has been correctly rebuilt.
Now if anyone can show me or rather document for all of us to see, an actually difference between a stock starter coil and a “High Torque” starter coil I would be willing to listen.
Denny Graham
Sandwich, IL

Denny G
Sandwich, IL