replacement 12 bolt rear

[Greg Barsamian]

Can a "stock" GM 12-bolt be machined to accept the 3.250 bearing to use an Aluminum Spool?

[NovaMan]

From a machining standpoint, I have to believe it's possible - it was done once when the housing was built. But from a strength standpoint, I suspect it would weaken the housing too much: your billet caps would probably take it, but there isn't much meat to spare ahead of them in the case, and it also wouldn't leave much metal between the bore and the bolts.


How do you remove the stock axle tubes, and where do you find DOM axle tubing?

[Alan Roehrich]

According to Mark Williams, yes, a stock housing can be machined to take the 3.250 bearing. They charge $550 or so. We have a stock housing in the car that takes the 3.250 bearing. But I think it was originally in a Kingwood Estate wagon, not a Camaro. If you want 3.250 bearings for an aluminum spool, buy the KTRE housing. It's not money well spent on a stock housing.

To remove the tubes, you cut them off flush with the housing, drill out the plug welds, and take a torch or a grinder and cut slots in the section of tube left in the housing. I did the 12 bolt in my Cutlass that way. I took the stock tubes, turned them down in a lathe, heated the housing, and drove them back in, plug weld them and then weld them all the way around. My housing is narrowed but the tubes are not cut and welded. WAY more work than most want to do. I'd say several of the steel supply companies can get you the tubing.