'67-'72 GM Dana 60's - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Bob B.** · 02-12-2022, 02:58 AM

Do full-floating Dana 60 differentials in '67-'72 GM trucks all take 30 spline shafts?

duallyjams · 02-13-2022, 09:51 AM

To my knowledge yes GM D60 rear axle are 30 spline. My D60 rear axle in my 68 K20 is 30 spline.

02-13-2022, 11:15 AM

I don't have any experience with this other than my 71 gmc , but the Dana 60 in it has 30 spline axles.

**Bob B.** · 02-13-2022, 06:24 PM

Thanks for the replys. Looking at getting a new Trac-Loc diff. and they come in different spline counts. 30 seems to be what all the older GM trucks used. Going to count mine just to be sure.

k29349 · 02-13-2022, 08:20 PM

Any reason you wouldn't go with a Detroit Truetrac instead?

**Bob B.** · 02-14-2022, 12:13 AM

Quote:

Originally Posted by k29349

Any reason you wouldn't go with a Detroit Truetrac instead?

No real reason other than I can get a deal on a 30 spline Trac-Loc. Truck never goes off road, the V-6 makes 220 H.P. and about 340 ft. lbs of torque, and I think the Trac-Loc was OEM.

**kwmech** · 02-14-2022, 01:40 AM

Quote:

Originally Posted by Bob B.

No real reason other than I can get a deal on a 30 spline Trac-Loc. Truck never goes off road, the V-6 makes 220 H.P. and about 340 ft. lbs of torque, and I think the Trac-Loc was OEM.

All I've ever seen in the 60s was a power-loc. The HO52 and 72 got a detroit as memory serves me. AND go with the Tru-trac as mentioned, you'll be happier in the long run

**Bob B.** · 02-14-2022, 02:37 AM

Thanks. Hearing a lot of good things about the True-Trac, I'll look into them. I am told they don't need friction modifier, that's a plus.

**special-K** · 02-14-2022, 08:22 AM

I really like the Tru-Trac. My experience has been with using in the front drive axle. I'm sure they are great in the rear. But I don't know any reason not to use the Trac-Loc if you've found a good deal on one.

duallyjams · 02-14-2022, 03:49 PM

I just bought a power loc for my D60. Talked with some dodge guys and that's what they recommend.

tdangle · 02-27-2022, 12:39 AM

I was looking in to the tru-trac and doesn't seem to be available anywhere in the 4.10 and down ratio with 30 spline axles.

**kwmech** · 02-27-2022, 01:20 AM

Tru trac Pn TT913A389

Availability might be another issue

02-12-2022, 02:58 AM	#1
Bob B. Senior Member Join Date: Aug 2005 Location: Los Angeles Posts: 1,321	'67-'72 GM Dana 60's Do full-floating Dana 60 differentials in '67-'72 GM trucks all take 30 spline shafts? __________________ 1967 GMC CM-2500 Camper Cruiser, 351E V-6, NP 435 4 speed, Dana 60, and factory A/C. 2012 GMC K-3500 WT regular cab, 6.0L Vortec, 6L90.

02-13-2022, 09:51 AM	#2
duallyjams Registered User Join Date: May 2007 Location: Deale Md Posts: 4,663	Re: '67-'72 GM Dana 60's To my knowledge yes GM D60 rear axle are 30 spline. My D60 rear axle in my 68 K20 is 30 spline. __________________ James 63 GMC V6 4speed carryall 65 chevy swb bbw V8 auto 68 K20 327/4 speed, buddy buckets 2002 GMC CC Dually Duramax 64 GMC lwb 3/4 V6 4speed SOLD 66 GMC swb bbw buddy buckets SOLD IG duallyjams The only thing that stays the same is constant change!

02-13-2022, 11:15 AM	#3
jeff74 Guest Posts: n/a	Re: '67-'72 GM Dana 60's I don't have any experience with this other than my 71 gmc , but the Dana 60 in it has 30 spline axles.

02-13-2022, 06:24 PM	#4
Bob B. Senior Member Join Date: Aug 2005 Location: Los Angeles Posts: 1,321	Re: '67-'72 GM Dana 60's Thanks for the replys. Looking at getting a new Trac-Loc diff. and they come in different spline counts. 30 seems to be what all the older GM trucks used. Going to count mine just to be sure. __________________ 1967 GMC CM-2500 Camper Cruiser, 351E V-6, NP 435 4 speed, Dana 60, and factory A/C. 2012 GMC K-3500 WT regular cab, 6.0L Vortec, 6L90.

02-13-2022, 08:20 PM	#5
k29349 Registered User Join Date: Nov 2013 Location: Inman S.C. Posts: 67	Re: '67-'72 GM Dana 60's Any reason you wouldn't go with a Detroit Truetrac instead?

02-14-2022, 02:37 AM	#8
Bob B. Senior Member Join Date: Aug 2005 Location: Los Angeles Posts: 1,321	Re: '67-'72 GM Dana 60's Thanks. Hearing a lot of good things about the True-Trac, I'll look into them. I am told they don't need friction modifier, that's a plus. __________________ 1967 GMC CM-2500 Camper Cruiser, 351E V-6, NP 435 4 speed, Dana 60, and factory A/C. 2012 GMC K-3500 WT regular cab, 6.0L Vortec, 6L90.

02-14-2022, 08:22 AM	#9
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,861	Re: '67-'72 GM Dana 60's I really like the Tru-Trac. My experience has been with using in the front drive axle. I'm sure they are great in the rear. But I don't know any reason not to use the Trac-Loc if you've found a good deal on one. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

02-14-2022, 03:49 PM	#10
duallyjams Registered User Join Date: May 2007 Location: Deale Md Posts: 4,663	Re: '67-'72 GM Dana 60's I just bought a power loc for my D60. Talked with some dodge guys and that's what they recommend. __________________ James 63 GMC V6 4speed carryall 65 chevy swb bbw V8 auto 68 K20 327/4 speed, buddy buckets 2002 GMC CC Dually Duramax 64 GMC lwb 3/4 V6 4speed SOLD 66 GMC swb bbw buddy buckets SOLD IG duallyjams The only thing that stays the same is constant change!

02-27-2022, 12:39 AM	#11
tdangle Registered User Join Date: Mar 2005 Location: Jurupa Valley, Ca Posts: 1,210	Re: '67-'72 GM Dana 60's I was looking in to the tru-trac and doesn't seem to be available anywhere in the 4.10 and down ratio with 30 spline axles. __________________ Terry 1970 Custom Camper/C20 , GM Crate 350/7004R, Dana 60, factory AC

02-27-2022, 01:20 AM	#12
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,504	Re: '67-'72 GM Dana 60's Tru trac Pn TT913A389 Availability might be another issue



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