Front Disc brake Conversion and rear end swap on C20 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Asshat · 06-12-2020, 10:26 PM

I’m sure many have done this, however, not sure if the best way to go is 5 or 6 lug. A rear end swap is inevitable too, and wondering if the higher gear rear ends are 5 or 6 lug.
Hoping someone could shed some light on possible solutions.

The 8 lug wheels are difficult to find, so converting the C20 to a C10 Drivetrain makes sense. Can anyone elaborate on what higher gear rear end would be ideal?

**The Rocknrod** · 06-13-2020, 05:16 AM

What year truck again?

**cwcarpenter98** · 06-13-2020, 06:39 AM

If you are keeping the stock engine and trans, something like a 3.08 would be a good highway gear. If you are going to swap in an overdrive transmission, 3.73s or 4.10s is the way to go. I have 3.73s and and overdrive trans in my truck and I spin around 2200 RPM to go 70mph.

Up until 70, all the factory 1/2 ton stuff was 6 lug. 71 to 87 1/2 ton 2wd is 5 lug.

Do you have coil springs or leaf springs in the rear?

Asshat · 06-13-2020, 09:55 AM

Quote:

Originally Posted by the rocknrod

what year truck again?

1963.

Asshat · 06-13-2020, 09:56 AM

Quote:

Originally Posted by cwcarpenter98

If you are keeping the stock engine and trans, something like a 3.08 would be a good highway gear. If you are going to swap in an overdrive transmission, 3.73s or 4.10s is the way to go. I have 3.73s and and overdrive trans in my truck and I spin around 2200 RPM to go 70mph.

Up until 70, all the factory 1/2 ton stuff was 6 lug. 71 to 87 1/2 ton 2wd is 5 lug.

Do you have coil springs or leaf springs in the rear?

It’s a combination of leaf and coil.

Asshat · 06-13-2020, 01:56 PM

Quote:

Originally Posted by cwcarpenter98

If you are keeping the stock engine and trans, something like a 3.08 would be a good highway gear. If you are going to swap in an overdrive transmission, 3.73s or 4.10s is the way to go. I have 3.73s and and overdrive trans in my truck and I spin around 2200 RPM to go 70mph.

Up until 70, all the factory 1/2 ton stuff was 6 lug. 71 to 87 1/2 ton 2wd is 5 lug.

Do you have coil springs or leaf springs in the rear?

I heard it was all 5 lug, then in the 80s it went to 6 lug.

Seems like I have to have my spindles machines down to work with 5 lug disc brakes, C10 style.

**cwcarpenter98** · 06-13-2020, 07:43 PM

If you want to run 5 lug, probably your easiest option will be to get a front cross member from a 73-87 so you can have an easier time getting replacement parts. Get the whole thing including the control arms and spindles. Drop spindles for the 1/2 tons are cheaper than the 3/4 tons

For your rear end, does it have trailing arms on the rear? If so, you could use a 71-72 rear end from a coil spring truck and it will bolt up no problem. If you want to use a squarebody rear, CaptainFab sells weld on mounts so you can mount to the trailing arms.

5 lug started in 71 for all half tons

**The Rocknrod** · 06-14-2020, 06:56 AM

Here is a thread on rear ends that fit our trucks - http://67-72chevytrucks.com/vboard/s...d.php?t=562446
I found it in the FAQ section - http://67-72chevytrucks.com/vboard/s...d.php?t=646002
There's even a thread on a 14-bolt conversion in there.

Asshat · 06-14-2020, 02:31 PM

Well, I'm still undecided. I guess I have three options:

1. Keep the 16.5 wheels and get new tires.

2. Get 8 lug, 16 inch wheels.

3. Find a conversion kit for the front and a different rear end.

At this point, I am good with option 1 or 2; if I keep the truck for a while I may just do the rear end so I have a taller gear.

Option 3 is probably going to cost a pretty penny.

06-12-2020, 10:26 PM	#1
Asshat Registered User Join Date: Jul 2015 Location: South Orange County CA Posts: 1,265	Front Disc brake Conversion and rear end swap on C20 I’m sure many have done this, however, not sure if the best way to go is 5 or 6 lug. A rear end swap is inevitable too, and wondering if the higher gear rear ends are 5 or 6 lug. Hoping someone could shed some light on possible solutions. The 8 lug wheels are difficult to find, so converting the C20 to a C10 Drivetrain makes sense. Can anyone elaborate on what higher gear rear end would be ideal?

06-13-2020, 05:16 AM	#2
The Rocknrod Moderator Join Date: Aug 2011 Location: China Spring, TX Posts: 7,280	Re: Front Disc brake Conversion and rear end swap on C20 What year truck again? __________________ Master Chief, US Navy, Retired 1964 C10 Step-side Short Bed - In Progress 2009 2500HD Duramax LTZ 1948 GMC Panel 1956 Big Window Stepside 1953 5 Window Chevy Stepside 1932 Coupe New Seat Foam for Bench Seats?

06-13-2020, 06:39 AM	#3
cwcarpenter98 Senior Member Join Date: Jan 2018 Location: Hickory Flat, GA Posts: 4,507	Re: Front Disc brake Conversion and rear end swap on C20 If you are keeping the stock engine and trans, something like a 3.08 would be a good highway gear. If you are going to swap in an overdrive transmission, 3.73s or 4.10s is the way to go. I have 3.73s and and overdrive trans in my truck and I spin around 2200 RPM to go 70mph. Up until 70, all the factory 1/2 ton stuff was 6 lug. 71 to 87 1/2 ton 2wd is 5 lug. Do you have coil springs or leaf springs in the rear? __________________ Christian Carpenter 1963 C10 - Frankentruck 283, Muncie 3 speed with overdrive Overdrive wiring here 1963-ish truck bed trailer - Half-Wit 1981 C10 - Penny 305, th350 --> Soon to be 350, Saginaw 4 speed 1995 Dodge Dakota Sport "I'll put it simple: if you're going hard enough left, you'll find yourself turning right." - Doc Hudson

06-13-2020, 07:43 PM	#7
cwcarpenter98 Senior Member Join Date: Jan 2018 Location: Hickory Flat, GA Posts: 4,507	Re: Front Disc brake Conversion and rear end swap on C20 If you want to run 5 lug, probably your easiest option will be to get a front cross member from a 73-87 so you can have an easier time getting replacement parts. Get the whole thing including the control arms and spindles. Drop spindles for the 1/2 tons are cheaper than the 3/4 tons For your rear end, does it have trailing arms on the rear? If so, you could use a 71-72 rear end from a coil spring truck and it will bolt up no problem. If you want to use a squarebody rear, CaptainFab sells weld on mounts so you can mount to the trailing arms. 5 lug started in 71 for all half tons __________________ Christian Carpenter 1963 C10 - Frankentruck 283, Muncie 3 speed with overdrive Overdrive wiring here 1963-ish truck bed trailer - Half-Wit 1981 C10 - Penny 305, th350 --> Soon to be 350, Saginaw 4 speed 1995 Dodge Dakota Sport "I'll put it simple: if you're going hard enough left, you'll find yourself turning right." - Doc Hudson

06-14-2020, 06:56 AM	#8
The Rocknrod Moderator Join Date: Aug 2011 Location: China Spring, TX Posts: 7,280	Re: Front Disc brake Conversion and rear end swap on C20 Here is a thread on rear ends that fit our trucks - http://67-72chevytrucks.com/vboard/s...d.php?t=562446 I found it in the FAQ section - http://67-72chevytrucks.com/vboard/s...d.php?t=646002 There's even a thread on a 14-bolt conversion in there. __________________ Master Chief, US Navy, Retired 1964 C10 Step-side Short Bed - In Progress 2009 2500HD Duramax LTZ 1948 GMC Panel 1956 Big Window Stepside 1953 5 Window Chevy Stepside 1932 Coupe New Seat Foam for Bench Seats? Last edited by The Rocknrod; 06-14-2020 at 07:01 AM.

06-14-2020, 02:31 PM	#9
Asshat Registered User Join Date: Jul 2015 Location: South Orange County CA Posts: 1,265	Re: Front Disc brake Conversion and rear end swap on C20 Well, I'm still undecided. I guess I have three options: 1. Keep the 16.5 wheels and get new tires. 2. Get 8 lug, 16 inch wheels. 3. Find a conversion kit for the front and a different rear end. At this point, I am good with option 1 or 2; if I keep the truck for a while I may just do the rear end so I have a taller gear. Option 3 is probably going to cost a pretty penny.



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