[ecordeddie]

seems like this topic comes up every time someone puts a set of adapters on their C3 to use a later Corvette wheel. Some guys have run adapters for thousands of miles with no trouble and other guys swear up and down that you won't make it out of your driveway before you have issues. Here's a really rough cross section of a stock wheel and a large backspace wheel on a stock hub and spindle. What's your take and why?

You have to make that call on your own based on your current Corvette.

The variables of Moment (spacer size 1/2"?, 2"?, 3"), amount of torque being delivered to the wheels (stock motor?, aftermarked crate?), and the age of your current bearings, how often you drive it, all come in to play.

The bigger the moment (more spacer you use), and the greater the torque = the more risk you have of bearing failure.

For example.....

My 1979's rear leaf spring is nearing the end of it's life. I can see some tilt inward of the rear wheels. So I know the bearings are already seeing some stress. I've also recently dropped in a new Crate 355 engine with 190 ft-lbs MORE torque than the stock engine....

If I go and add 2-inch spacers to the mix I'll be upping the moment arm on the bearings by a factor of about 17%. (2"/12" = 0.1666')

So now I've added 17% more moment arm to the bearings, added 190 ft-lbs of more toqure to the bearings, and I know my leaf springs got a sag as well also adding more stress to the bearings.

For me, I'd say it'd be a medium risk of bearing failure.