For Those Doing Disk Brakes. 60-66

[lolife99]

Originally Posted by Mjminino

Seems like this answer is all sporadic.

I have a 1964 C10, in y'alls opinion, what is the cheapest way to convert my rear 6 lug to 5 lug for disk brakes? Going to a junkyard and finding a 5 lug rear end if so, what years?

Mike

71-72 rearend, or Moser Engineering axles from Summit Racing.
(usually free shipping)

[Mjminino]

Yeah earliest year here in Omaha is a 77 and I'm sure there would be some fabrication tonuse that rear end?

Could I take my current spindles to a machine shop and have them drill new holes? And just use captian's disk brake plates?

[Blu64c10]

Originally Posted by Mjminino

Yeah earliest year here in Omaha is a 77 and I'm sure there would be some fabrication tonuse that rear end?

Could I take my current spindles to a machine shop and have them drill new holes? And just use captian's disk brake plates?

Mjminino,my build thread shows how I filled my 6 lug pattern and redrilled for 5 lug, any machine shop should be able to do this.

http://67-72chevytrucks.com/vboard/s...=642354&page=2

[Captainfab]

Yes you can have your original 6 lug axles plugged and redrilled to 5 x 5. I would only do that if the bearing surfaces are in excellent condition. If you need new axles, I believe you will have to go with 30 spline axles, which means changing the spider gears also. You can change the entire differential for a 10 bolt or 12 bolt up thru '86 in the C10's and '87-'91 in the R1500's. You will have to cut off all the original spring pads and shock mounts and weld on trailing arm mounts (I make those) and also the panhard bar mount. Those will all be 1.5" wider than your current 12 bolt. If you were able to find a '71-'72 12 bolt it would also be 1.5" wider.

[OldGMJon]

I was hoping to switch a complete donor 80' Chevy C30 front cross member onto my 66' GMC 2503. Are the C30 cross members different in any significant way for those years? Would a rear end swap go in cleanly as well? Maybe the front (disk/power) cross member would be a better fit on my 65' C10 lwb with 350 & a 3 on the tree? Opinions?

Originally Posted by Captainfab

Yes. You can change the entire differential for a 10 bolt or 12 bolt up thru '86 in the C10's and '87-'91 in the R1500's. You will have to cut off all the original spring pads and shock mounts and weld on trailing arm mounts (I make those) and also the panhard bar mount.

[Captainfab]

A '73-'87 C30 front crossmember will fit your '66 GMC just fine. The C30's are basically the same as a C10 or 20. You will have to drill one hole on each side and elongate one hole each side. I don't remember the measurement but I do believe a '80 C30 differential will need the spring pads moved to bolt up under your GMC. It also depends on whether the C30 is a C&C or a pickup.

Originally Posted by OldGMJon

I was hoping to switch a complete donor 80' Chevy C30 front cross member onto my 66' GMC 2503. Are the C30 cross members different in any significant way for those years? Would a rear end swap go in cleanly as well? Maybe the front (disk/power) cross member would be a better fit on my 65' C10 lwb with 350 & a 3 on the tree? Opinions?

[OldGMJon]

Originally Posted by Captainfab

A '73-'87 C30 front crossmember will fit your '66 GMC just fine. The C30's are basically the same as a C10 or 20. You will have to drill one hole on each side and elongate one hole each side. I don't remember the measurement but I do believe a '80 C30 differential will need the spring pads moved to bolt up under your GMC. It also depends on whether the C30 is a C&C or a pickup.

Thanks for responding Captn...
You're speaking of the Leaf Spring pads that need moving I gather?
The C30's are flatbeds...
I thought why not just install the whole drivetrain, front sup., rear end, trans, and engine from the 80' C30 into the 66' 2503.
Will I need to use everything including; the engine mounts, the steering box & pump, the steering column, etc.?
Are the chassis' the same length/will I be able to use either's driveshaft?
What is the gearing in an 80' C30 trans(4sp/lowest granny) and rear end?
Will this switch be worth the effort?
I appreciate hearing from the guys in the know...thanks again Captain.
jon
ps: the flatbed on the 80' C30 will look perfect on my 64' C30 and to complete the 66' GMC 2503 I got a 65' GMC I1500 for most other parts I'll need.

[Captainfab]

Yes I am talking about the leaf spring pads. You can use as much or as little of the donor '80 C30 as you want. It's hard to say what the differential gears are. I would think 4.10-1. There are a few different wheel bases with the C30's so it's hard to say about the driveshaft. If you will be using the SM465 from the '80 C30, you might be best off to use the '80 driveshaft? Just have to take a look at it and see what will workout best. Yes I do feel it is worth the work for the conversion.

[OldGMJon]

Originally Posted by Captainfab

You can use as much or as little of the donor '80 C30 as you want. The differential gears I would think are 4.10-1. There are a few different wheel bases for the C30 so it's hard to say about the driveshaft. If you will be using the SM465 from the '80 C30, you might be best off to use the '80 driveshaft? I do feel it is worth the work for the conversion.

Thanks Captain...both C30's have the 9 foot flatbeds so I am hoping on a driveshaft fitment. Curious as to the freeway speeds/rpms the 80's drivetrain setup should afford me in the 66'...I had a 64' F350 flatbed that maxed out at 45mph...I took it faster a few times but the R's were deafening. I haven't had any of these c30's on the road over 45 mph yet to know what they can do.

[Captainfab]

In my experience most of the '60's C20's and C30 came with 4.57 gears and some C30's had 5.14's. The 4.10's aren't a huge improvement over 4.56's but enough to make a difference. You can always go with a 85 (235/85R16) series tire to help lower the rpm's some more.

[OldGMJon]

Originally Posted by Captainfab

In my experience most of the '60's C20's and C30 came with 4.57 gears and some C30's had 5.14's. The 4.10's aren't a huge improvement over 4.56's but enough to make a difference. You can always go with a 85 (235/85R16) series tire to help lower the rpm's some more.

Thanks Captain
I didn't even think of a tire switch.
jon

[OldGMJon]

Originally Posted by Captainfab

. You can always go with a 85 (235/85R16) series tire to help lower the rpm's some more.

Hi Captainfab, I decided to switch the 80' C30 drive train to my 64' C30. The 80' C30 has a hydro boost power brake set up so I will need a mounting bracket set up to fit my 64' engine compartment. Do you make those? jon

[Captainfab]

Yes. I replied to your PM regarding this.

Originally Posted by OldGMJon

Hi Captainfab, I decided to switch the 80' C30 drive train to my 64' C30. The 80' C30 has a hydro boost power brake set up so I will need a mounting bracket set up to fit my 64' engine compartment. Do you make those? jon

[DOUBLE-DINGO]

Wow it's been 8 years! Crazy. I finally did this swap. Not having a garage and fearing parts walking off I didn't do the swap to the original truck I started on. In April 2015 I bought another '65, I'm the third owner, and have been upgrading stuff since I got it. I finished the disc conversion on Thanksgiving Day. What a huge improvement. I am very disappointed in CPP kit that I bought for just under $1,000 that came with ball joints with nuts that didn't sit snug on the studs. There was no way they could have been torqued to spec, and even if they could, I fear they would have separated on the first hard bump in the road. The tie-rods were metric, the brake hoses were wrong, the pads are inferior, so all I used from the kits was the spindles, rotors, and calipers. Had to buy new hoses, pads, hoses, tie-rods, and bearings. Then the MPB booster/master cylinder kit I bought was wrong too. Sadly I bought all this stuff years before doing the swap, and when I bought it I was told it was all a direct bolt-in. Lesson learned.

The swap is not that bad, just frustrating getting the finite details ironed out.