Axle swap help.. 2wd 3/4ton with coils - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Big69C20 Toy · 06-12-2003, 06:10 PM

Ok fellas as it seems i'm driving a LONG distance i thought that swapping out my rear end might be an option. As it sits now i've got that nice HO72 rear with 4.10 gearing... so mileage isn't happenin' even for a BB (yeah i know 'mileage' is never an option)

Anyone out there know what i can put under the rear of this thing EASILY with TALL, numerically low, gears.. i'm not talking 3.73 or something i mean low 3 or somethign in the 2s... this truck is not gonna need the torque as the motor more than has that covered.

Suggestions greatly appreciated.
Thanks
Greg

crazy longhorn · 06-12-2003, 06:48 PM

you might do a search in eng& driveline, there was a post a while back on the dana 61(found in some Ford trucks), that would be around 3 to 1 gearing. It would be a weld in swap tho....good luck,crazyL

Longhorn Man · 06-12-2003, 07:36 PM

As far as afordable bolt in...I think you are about as good as you'll get.
I'll trade you for my 4.56 rear.

Big69C20 Toy · 06-12-2003, 10:06 PM

rats... not what i was hoping but thanks guys

Big69C20 Toy · 06-13-2003, 05:38 AM

ttt any other suggestions? i'd really rather not run this motor at 3000+ for 2500 miles...
thanks

Mike C · 06-13-2003, 08:41 AM

35" tires will fit in the back with no lift...

For bolt in 8 lug, Dana 60 coil with 3.54 is out there, but you probably should have been looking for awhile...

Another option would be to swap in a 12 bolt with 3.07 and just throw the HO52 in the bed. Make sure and get a 6 lug spare to go with your 8 lug, however.

Rumor has it that there may have been a lower 3 series HO52/72, but no confirmations. ANd obviously that will be hard to find.

Big69C20 Toy · 06-13-2003, 12:51 PM

hmm so the C10 axles will pop right in there huh Mike? i was wondering on that one and that way i'd just toss my old axle in the back.

Anyone know of any differences between the fittament of the C20 and C10? It'd probly be easier and cheaper to pick one of those up if the fit is a swap. thanks all

**COBALT** · 06-13-2003, 01:55 PM

HO52/72 axles would take an older 3.73 gear set about 1000 years ago, but that's the lowest in gear reduction you could go. They're rare, and almost impossible to find so I wouldn't bother. 3.90 is the lowest you can go in those axles right now, and that's off-the-shelf new for around $250 uninstalled.

I've been salivating over the aftermarket Dana 60s that are out there....I'm saving my $$$.

Mike C · 06-13-2003, 03:44 PM

The only real issues I see is the bore diameter of the brake wheel cylinders and the length of the back half of the driveshaft might be different. But running through a parts store catalog should be able to turn up wheel cylinders with approximatly same diameter as the HO. Get the driveshaft from the donor truck you get axle from.

Cobalt, why an aftermarket 60? They are reasonably easy to find original ones. I have 3. One in my 70 GMC, one in the long step parts 70 GMC, and one in the Longhorn 70 GMC parts truck. All leaf spring however, but I have looked at coil spring 60's in Chevys. The Longhorn has 40" spring centers just like the 4x4, so I plan on swapping that one into my Jimmy with the 4.10 gears from the longstep.

**COBALT** · 06-13-2003, 04:36 PM

Some of the new ones have deflection screws that keep the carrier from flexing under high loads (hint hint). They also yield more options when it comes to brakes and other accessories - plus they don't have the saddles welded on so you can put them in leaf or coil spring suspensions. They also look cool as hell...

Just something I've been dreaming about...

Mike C · 06-13-2003, 10:29 PM

I don't think I have ever seen a failure on a bearing cap on a 60. Regardless of the power. And I have seen plenty of 8 second drag cars with 60's. You can always add an aluminum cover that has the cap reinforcing bolts in it.

I just built a Chevelle 12 bolt and installed a Tom's steel cap on the drivers side. IMO, it weaked the casting and I would have used the stock cap with the girdle cover.

I built my own rear for my 68 Camaro convertible. It started out as a 65 Impala housing with all of the coil spring trailing arm brackets. The cutting torch and grinder made quick work of that! It is narrowed to the stock Camaro width and the big car ends allow the Corvette caliper brackets to be bolted to it. No reason to buy new! It has Mopar housing leaf spring mounts on it in the pic, but I have since cut them off and replaced them with repop Camaro multi-leaf mounts. Save your money and get you a bolt in 60 from a 67-72!

Dan72cst · 06-14-2003, 12:47 AM

For whatever its worth. .....Another option would be to go with an overdrive tranny and leave the rear end alone.

da-burb · 06-14-2003, 01:03 AM

Your panhard bar is different and has different frame mounts from 12 bolt to Dana 60 to Eaton/Corp. I do have a spare Dana 60, coil mount with 3.54 gears. It isn't going to be cheap because it is posi. California to Michigan via Minnesota??

06-12-2003, 06:10 PM	#1
Big69C20 Toy Livin' it up. Join Date: Nov 2001 Location: Richland, MI Posts: 2,212	Axle swap help.. 2wd 3/4ton with coils Ok fellas as it seems i'm driving a LONG distance i thought that swapping out my rear end might be an option. As it sits now i've got that nice HO72 rear with 4.10 gearing... so mileage isn't happenin' even for a BB (yeah i know 'mileage' is never an option) Anyone out there know what i can put under the rear of this thing EASILY with TALL, numerically low, gears.. i'm not talking 3.73 or something i mean low 3 or somethign in the 2s... this truck is not gonna need the torque as the motor more than has that covered. Suggestions greatly appreciated. Thanks Greg __________________ -Greg; Sold the 69 C20. It's off to a better home with more love! Now onto the 86 CUCV M1009; K5 blazer with 6.2L diesel, corp 10 bolt axles, Detroit locker in the rear, trutrac front, 3.73 gears, 35" tires.

06-12-2003, 06:48 PM	#2
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	you might do a search in eng& driveline, there was a post a while back on the dana 61(found in some Ford trucks), that would be around 3 to 1 gearing. It would be a weld in swap tho....good luck,crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

06-12-2003, 10:06 PM	#4
Big69C20 Toy Livin' it up. Join Date: Nov 2001 Location: Richland, MI Posts: 2,212	rats... not what i was hoping but thanks guys __________________ -Greg; Sold the 69 C20. It's off to a better home with more love! Now onto the 86 CUCV M1009; K5 blazer with 6.2L diesel, corp 10 bolt axles, Detroit locker in the rear, trutrac front, 3.73 gears, 35" tires.

06-13-2003, 05:38 AM	#5
Big69C20 Toy Livin' it up. Join Date: Nov 2001 Location: Richland, MI Posts: 2,212	ttt any other suggestions? i'd really rather not run this motor at 3000+ for 2500 miles... thanks __________________ -Greg; Sold the 69 C20. It's off to a better home with more love! Now onto the 86 CUCV M1009; K5 blazer with 6.2L diesel, corp 10 bolt axles, Detroit locker in the rear, trutrac front, 3.73 gears, 35" tires.

06-13-2003, 08:41 AM	#6
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,713	35" tires will fit in the back with no lift... For bolt in 8 lug, Dana 60 coil with 3.54 is out there, but you probably should have been looking for awhile... Another option would be to swap in a 12 bolt with 3.07 and just throw the HO52 in the bed. Make sure and get a 6 lug spare to go with your 8 lug, however. Rumor has it that there may have been a lower 3 series HO52/72, but no confirmations. ANd obviously that will be hard to find. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

06-12-2003, 07:36 PM	#3
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	As far as afordable bolt in...I think you are about as good as you'll get. I'll trade you for my 4.56 rear.

06-13-2003, 12:51 PM	#7
Big69C20 Toy Livin' it up. Join Date: Nov 2001 Location: Richland, MI Posts: 2,212	hmm so the C10 axles will pop right in there huh Mike? i was wondering on that one and that way i'd just toss my old axle in the back. Anyone know of any differences between the fittament of the C20 and C10? It'd probly be easier and cheaper to pick one of those up if the fit is a swap. thanks all __________________ -Greg; Sold the 69 C20. It's off to a better home with more love! Now onto the 86 CUCV M1009; K5 blazer with 6.2L diesel, corp 10 bolt axles, Detroit locker in the rear, trutrac front, 3.73 gears, 35" tires.

06-13-2003, 01:55 PM	#8
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	HO52/72 axles would take an older 3.73 gear set about 1000 years ago, but that's the lowest in gear reduction you could go. They're rare, and almost impossible to find so I wouldn't bother. 3.90 is the lowest you can go in those axles right now, and that's off-the-shelf new for around $250 uninstalled. I've been salivating over the aftermarket Dana 60s that are out there....I'm saving my $$$. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

06-13-2003, 03:44 PM	#9
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,713	The only real issues I see is the bore diameter of the brake wheel cylinders and the length of the back half of the driveshaft might be different. But running through a parts store catalog should be able to turn up wheel cylinders with approximatly same diameter as the HO. Get the driveshaft from the donor truck you get axle from. Cobalt, why an aftermarket 60? They are reasonably easy to find original ones. I have 3. One in my 70 GMC, one in the long step parts 70 GMC, and one in the Longhorn 70 GMC parts truck. All leaf spring however, but I have looked at coil spring 60's in Chevys. The Longhorn has 40" spring centers just like the 4x4, so I plan on swapping that one into my Jimmy with the 4.10 gears from the longstep. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

06-13-2003, 04:36 PM	#10
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Some of the new ones have deflection screws that keep the carrier from flexing under high loads (hint hint). They also yield more options when it comes to brakes and other accessories - plus they don't have the saddles welded on so you can put them in leaf or coil spring suspensions. They also look cool as hell... Just something I've been dreaming about... __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

06-13-2003, 10:29 PM	#11
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,713	I don't think I have ever seen a failure on a bearing cap on a 60. Regardless of the power. And I have seen plenty of 8 second drag cars with 60's. You can always add an aluminum cover that has the cap reinforcing bolts in it. I just built a Chevelle 12 bolt and installed a Tom's steel cap on the drivers side. IMO, it weaked the casting and I would have used the stock cap with the girdle cover. I built my own rear for my 68 Camaro convertible. It started out as a 65 Impala housing with all of the coil spring trailing arm brackets. The cutting torch and grinder made quick work of that! It is narrowed to the stock Camaro width and the big car ends allow the Corvette caliper brackets to be bolted to it. No reason to buy new! It has Mopar housing leaf spring mounts on it in the pic, but I have since cut them off and replaced them with repop Camaro multi-leaf mounts. Save your money and get you a bolt in 60 from a 67-72! __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

06-14-2003, 12:47 AM	#12
Dan72cst Registered User Join Date: Feb 2001 Location: Lake Stevens,WA 98258 North of Seattle Posts: 833	For whatever its worth. .....Another option would be to go with an overdrive tranny and leave the rear end alone. __________________ Marysville, WA (Dan72cst@hotmail.com) 72 4wd Blazer CST 350/350 72 4wd Chevy LWB 350/350 68 2wd Chevy LWB 327/400

06-14-2003, 01:03 AM	#13
da-burb "Ochre Ogre" Join Date: Apr 2000 Location: Springfield, MN Posts: 3,558	Your panhard bar is different and has different frame mounts from 12 bolt to Dana 60 to Eaton/Corp. I do have a spare Dana 60, coil mount with 3.54 gears. It isn't going to be cheap because it is posi. California to Michigan via Minnesota?? __________________ Bowtie Truck Stop Inc. Mid-West GM Truck Restoration Parts Supplier Your Key Parts, Auto Metal Direct, Dynacorn, and Goodmark dealer. like us @ www.facebook.com/BowtieTruckStop 1971 C-10 Suburban (Ochre) 1971 K-10 Suburban (Ochre) 1972 C-10 Suburban (Ochre) 1972 K-20 Suburban (Yellow- that just aint right!) Springfield, Minnesota 56087



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