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Blaze69 · 12-02-2002, 02:38 PM

Well I finally got my donor front end. Now I need someone to decode the numbers to see exactly what it is. Here goes: 603675 1 4130 6 7ce.

As you may have guessed I got it for the front disc option. Here's a question for the guru's out there.
I took the proportioning valve from the donor also. My old valve on my '69 had two inputs and two outputs, the donor had two inputs and three outputs (one for each front caliper and a larger one to feed the back). Should I use the donor and modify my old lines to accept the inputs and create a new line for the extra output?

I am also going to buy new rubber lines to feed the calipers and cylinders.

If in fact it's worth the time and effort, what would be the best way to modify the lines? Should I/can I buy a setup like this? Or should I just buy some line, bend it myself and go from there?
Thanks, I'm going out to start taking the axle apart and view the insides.

**Classic Heartbeat** · 12-02-2002, 02:52 PM

I don't know what proportioning valve you have, but it should only have 2 inputs and 2 outputs with the one that goes to the front disk brakes being smaller. On both my 72 K-5, 72 3/4 ton 4X4 and 72 1/2 ton 4X4 the front brake lines are smaller diameter than the rear. I do know that you will need to change it or you will have problems with your brakes. The front brakes could possibly lock up, because they require less pressure than the rear drum brakes. I would at least go to one that is set up for 71-72 trucks or buy an adjustable one. WES www.ClassicHeartbeat.com

**Classic Heartbeat** · 12-02-2002, 02:56 PM

I think you will have to have your own brake lines made if you change them. I don't know any company that is reproducing them for the 4X4s yet. WES www.ClassicHeartbeat.com

Blaze69 · 12-02-2002, 03:03 PM

If it makes any difference the donor is a '76 blazer. Did they change something then?

**Classic Heartbeat** · 12-02-2002, 04:21 PM

I believe the location of the proportioning valve is different. Not possitive though.. The proportioning valves are different also. 71-72 C-K has one part number, 73-75 C-K are another number and 76-77 are another number. It also matters if you have power brakes in 74-77 and 78-83 or not. WES www.ClassicHeartbeat.com

12-02-2002, 02:38 PM	#1
Blaze69 Registered User Join Date: Apr 2001 Location: Arizona Posts: 147	Finally got it! Well I finally got my donor front end. Now I need someone to decode the numbers to see exactly what it is. Here goes: 603675 1 4130 6 7ce. As you may have guessed I got it for the front disc option. Here's a question for the guru's out there. I took the proportioning valve from the donor also. My old valve on my '69 had two inputs and two outputs, the donor had two inputs and three outputs (one for each front caliper and a larger one to feed the back). Should I use the donor and modify my old lines to accept the inputs and create a new line for the extra output? I am also going to buy new rubber lines to feed the calipers and cylinders. If in fact it's worth the time and effort, what would be the best way to modify the lines? Should I/can I buy a setup like this? Or should I just buy some line, bend it myself and go from there? Thanks, I'm going out to start taking the axle apart and view the insides. __________________ 1969 Blazer: 350/350, 4X4, HEI, Edlebrock carb/intake, dual flowmasters, np205, 3:07's and the rest is mostly stock. The front end disc swap is finally complete 2002 Z71 Tahoe. CAI, Flowmaster 40, Silverstars in high, low and fogs and a bunch of mods (upgrades) inside and out.

12-02-2002, 02:52 PM	#2
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,768	I don't know what proportioning valve you have, but it should only have 2 inputs and 2 outputs with the one that goes to the front disk brakes being smaller. On both my 72 K-5, 72 3/4 ton 4X4 and 72 1/2 ton 4X4 the front brake lines are smaller diameter than the rear. I do know that you will need to change it or you will have problems with your brakes. The front brakes could possibly lock up, because they require less pressure than the rear drum brakes. I would at least go to one that is set up for 71-72 trucks or buy an adjustable one. WES www.ClassicHeartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

12-02-2002, 02:56 PM	#3
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,768	I think you will have to have your own brake lines made if you change them. I don't know any company that is reproducing them for the 4X4s yet. WES www.ClassicHeartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

12-02-2002, 03:03 PM	#4
Blaze69 Registered User Join Date: Apr 2001 Location: Arizona Posts: 147	If it makes any difference the donor is a '76 blazer. Did they change something then? __________________ 1969 Blazer: 350/350, 4X4, HEI, Edlebrock carb/intake, dual flowmasters, np205, 3:07's and the rest is mostly stock. The front end disc swap is finally complete 2002 Z71 Tahoe. CAI, Flowmaster 40, Silverstars in high, low and fogs and a bunch of mods (upgrades) inside and out.

12-02-2002, 04:21 PM	#5
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,768	I believe the location of the proportioning valve is different. Not possitive though.. The proportioning valves are different also. 71-72 C-K has one part number, 73-75 C-K are another number and 76-77 are another number. It also matters if you have power brakes in 74-77 and 78-83 or not. WES www.ClassicHeartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys



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