350 Starter holes drilled incorrectly?

[GRADYS Performance]

Bolting the Torque Converter up to the Flexplate should not move the Flexplate at all. Modifying the starter gear may not get the results you want.

Originally Posted by Gibson

Cool - I'm going to do one last set of measurements tonight after I get the converter bolted back up and torqued down just so I have the block-to-flexplate gap documented. I measured it last night with the flexplate free, and it was right around .5 - so already a bit too far out based on ron's measurements. That is only going to get farther when torqued down, so I'm a bit worried already. We shall see!

[Gibson]

Well, it is confirmed. Stacking tolerances (and possibly a bur or some debris) seem to be at the root of this problem.

I was fortunate enough to get some help from a long time mechanic and auto vocational teacher tonight. He confirmed that the flexplate looked correct, as did the mate between crank and flexplate and block and bellhousing. Also he checked the converter clearance, and it was within spec. After torquing down the blots on the converter, there was no shift in the flexplate location. I now suspect there might have been a piece of trash or something where the converter mates up which was part of the cause of the excessive flexplate runout (the gap between starter and flexplate is STILL on the large side, but not as bad as it was when the flexplate was bolted up before)

Tonight we mounted an OEM style starter which appears to have enough throw for proper engagement. Gradys was right about modifying the gear - that won't work. The flange on the back is what the thrust bearing/fork thingy pushes against. Instead, I will go with what Powermaster support suggested and machine the body of the starter a bit. It would still need to be modified to work properly.

For now, I'm just going to enjoy being able to start it with the OEM style starter!

Thanks to everyone for the help! If someone runs into this in the future and has this same problem, I would recommend they first unbolt the converter from the flexplate, ensure proper converter/flexplate clearances, and torque things back down to spec and see where they are. Also, try an OEM style starter first and make sure the problem still exists.