Bought an IMI Hi Torque starter for my '67. Originally a 326, but I put a '69 400 ci, but am using the 326 ring gear/flex plate. Installed it yesterday and it makes a screeching noise when I start it, which I initially thought was just the mating call of my Bird, but in reality is more likely my flex plate being annihilated. The tolerance between the starter pinion and ring gear was adjusted to spec at ~0.100" but I was having trouble adjusting the ring gear backlash. The instructions say to pull the starter pinion out with a screwdriver and check the backlash, but the starter pinion kept hitting the ring gear directly and wouldn't fully mesh. I added shims and the pinion would mesh, but not fully retract. So more shims. Finally it would not bind up. I pulled to coil and cranked and it seemed fine. Then after hooking the coil back up the first start a yielded a real nice squawk. Can't be good. I dropped the starter again (I probably had it on and off like 4-5 times) and added another shim. Still squawking. I feel like adding a whole pack of shims is a bit excessive right? I ended up just calling it a day and putting her back into hibernation. I'll probably call IMI again. I had an extra wire and they explained since I switched to electronic ignition the other wire was obsolete. Really helpful, but I was curious if you had any personal experience. Also found this, which couldn't be any more specific to my application, but who knows. http://www.highperformancepontiac.com/tech/hppp_0912_hi_torque_mini_starter/viewall.html
So I guess my questions are: 1. Have you had any similar experiences? 2. How many shims are too many? I'm proably at about 0.25"