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4x4Poet · 02-11-2006, 04:17 PM

Front: What's been said about swapping in 3/4 ton stuff from the spindle out. I forget if the caliper brackets must also be swapped out.
Another upgrade is to install superior, 73up inner axles at the same time since they don't neck down as much and use a Spicer 760x joint (replacement for the old 297x) that is beefier than the original '72 260x joint. Consider alloy axles if the budget allows. Inner and stub Yukon 4340 axles can be had for both sides thru ringpinion.com/ for ~$450 with 760x joints plus shipping. Only absolutely necessary with a locker, IMO. Superior makes bling bling versions for much bigger bucks.

Rear: AFAIK, only 77up 1-ton GM trucks had SRW 14bFFs with the axle perches spaced to match 67-72s. I'm pretty sure that any other 14bFF must have its spring perches relocated to match the spring width of your '72 K10. No biggie if you can do it yourself or get the axle cheap so as to leave budgetary room for the short fab work. Proper angle is as important as width to stave of any castor-induced driveline vibration.

A cheaper option might be to source an Eaton H052 rear axle with 4.11 gears. It would also be light weight to retain a desent ride. Many 67-72 truck owners notice a tad more ride harshness once they install a 14bFF over an Eaton H052 or the 12-bolt. With either the Eaton or 14bFF, changing to disc brakes helps reduce the weight for a better ride, not to mention better stopping and easier maintenance (pad or caliper R&R).

02-11-2006, 04:17 PM	#13
4x4Poet Registered User Join Date: Nov 2004 Location: "Under Montana skies." Posts: 1,836	Front: What's been said about swapping in 3/4 ton stuff from the spindle out. I forget if the caliper brackets must also be swapped out. Another upgrade is to install superior, 73up inner axles at the same time since they don't neck down as much and use a Spicer 760x joint (replacement for the old 297x) that is beefier than the original '72 260x joint. Consider alloy axles if the budget allows. Inner and stub Yukon 4340 axles can be had for both sides thru ringpinion.com/ for ~$450 with 760x joints plus shipping. Only absolutely necessary with a locker, IMO. Superior makes bling bling versions for much bigger bucks. Rear: AFAIK, only 77up 1-ton GM trucks had SRW 14bFFs with the axle perches spaced to match 67-72s. I'm pretty sure that any other 14bFF must have its spring perches relocated to match the spring width of your '72 K10. No biggie if you can do it yourself or get the axle cheap so as to leave budgetary room for the short fab work. Proper angle is as important as width to stave of any castor-induced driveline vibration. A cheaper option might be to source an Eaton H052 rear axle with 4.11 gears. It would also be light weight to retain a desent ride. Many 67-72 truck owners notice a tad more ride harshness once they install a 14bFF over an Eaton H052 or the 12-bolt. With either the Eaton or 14bFF, changing to disc brakes helps reduce the weight for a better ride, not to mention better stopping and easier maintenance (pad or caliper R&R). __________________ '71 GMC K20 Suburban, '71 GMC K10 Suburban, '72 Chevy C10 CST Suburban, '72 Chevy K20 clunker pickup.