Please help me get to the bottom of this goofy problem. It has been driving me crazy. I put a 1999 454 in my 72 Chevelle. It was supposed to be a drop in motor. It wasn't
The starters and flywheel are being chewed up to the point I had to replace 3 starters and one flywheel. Here is what I have done.

1) bought the correct starter (bought from Car Quest)
2) Replce the flywheel with a GM (Bought from the dealer)
3) Found out I had the incorrect bolts for the starter I had SAE 3/8 and should have been Metric 10mm.
4) GM said you do not need shims or support bracket with this starter. The starter has a gear reduction so nothing should be needed. :sad:
Any advice or new leads would be TERRIFIC. I really do not want to bring it to a dealer,
Thanks George :beers:

4) GM said you do not need shims or support bracket with this starter. The starter has a gear reduction so nothing should be needed. :sad:
Thanks George :beers:

Shim(s) are needed! You are either too loose, too tight, or crooked. I assume that you have REAL starter bolts, so crooked should not be the problem. Real starter bolts have the knurl section at the starter to block interface and make the starter parallel to the crankshaft. So you are too tight or too loose. Too tight should growl like a bear. Get a service book form the library and get the measurement & adjustment procedure. Perhaps someone has this handy and will post it.

Did you use regular hardware store bolts or the GM knurled bolts? A regular bolt will bend and twist allowing the starter to move away from the flywheel.

Thanks for the suggestions. I used the correct bolts from Carquest, (so he said)10 mm not 3/8 for 99 block. I thought that should ahve corrected the problem, but I am still having problems. I spoke to a GM service rep. about the shims and he said "with the correct starter you should not need shims". What is so strange about this problem is that when I first put the starter on, it works great for about 10 time and then starts acting up.
Thanks George

I didn't understand your response fully so will add a little more clarity to my response.

I am not familiar with what was used in 1999, however in earlier years the bolts are thicker or shouldered on the shaft that goes through the starter holes. With the starter off the car place the bolts through the holes. If your bolts have any play or wiggle at all, the torque of the starter motor will cause it to push the starter away from the flywheel. The incorrect bolts will also bend. Just because the bolts you use are the right length and thread pitch doesn't mean they will do the job.

I know this from first-hand experience. ;)