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Old 10-09-2017, 09:54 PM   #1
SunSoaked
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Cucv axles swap-k20, brake concern

In the process of swapping 14ff/Dana 60 into my 85 K20. I spec'd a new m/c for the k30. I'm wondering if the combination valve located on the frame horn cross member needs attention? Anybody have any input on this? Appreciate the help.
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Old 10-10-2017, 08:00 AM   #2
cadillac_al
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Re: Cucv axles swap-k20, brake concern

I put a Dana 60 on my 76 K20 and didn't do anything with the brakes. Same master and combination valve and it works fine.
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Old 10-10-2017, 12:21 PM   #3
Ziegelsteinfaust
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Re: Cucv axles swap-k20, brake concern

The cucv likely used hydroboost. Which can be a better brake system since it allows more pressure to be applied.

Like stated above you do not need to switch anything more to make the set up work.
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Old 10-10-2017, 12:59 PM   #4
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Re: Cucv axles swap-k20, brake concern

as said it can work .

but to be 100% correct the 1/2 and 3/4 ton calipers are smaller piston size over the 1ton dana 60 size . so they require more volume of fluid .

lots have gotten away with this swap and been happy . and lots have not been happy .

if you can get the hydroboost parts and brake pedal and the lines and pump from the doner truck and swap them in . you will like the hydroboost better over vac brakes .
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Old 10-10-2017, 01:35 PM   #5
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Re: Cucv axles swap-k20, brake concern

Thanks for the info. I'm doing major conversions on the truck over the next few months. Stage one is the axle swap, then the hydroboost, serpentine setup, edelbrock pro-flow and the nv 4500/205 swap. I have the hydroboost/hydraulic pedal assembly as well as the manual trans/tilt steering column ready to go (driveline mods tbd).
Regarding the brakes- I was just wondering if that valve would affect the bias of the brakes, assuming it's even different between a K20/30? I assume it's a combination valve (proportion/pressure loss warning) thing. Looking at it the other way-if I put the K20 valve in a stock cucv, would it have any effect?

Last edited by SunSoaked; 10-10-2017 at 01:41 PM.
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