OK. Just to show my ignorance here - isnt the proportioning valve the silver thing with the lines on the side (drivers) below the MC ? I do believe its a disk/disk MC my memory just is getting bad on these things and bought it like 2 years ago. So I was thinking thats just a direct hookup and would only need either a residual or adjustable valve if that one wasnt working.
eg looks like this just to side of MC - but silver
https://www.carolinaclassictrucks.co...p-Valve-1.html
yep, that is the stock valve and the wire connection would go to a dash light that indicated brake trouble. whe a line blows off or some other problem happens in one brake circuit the other brake circuit is still pressured up which causes a piston in that valve to move over and close the circuit in that switch. that prop valve may or may not work for your brake application because it is set up for the vehicle it came from which may not have the same brake bias as you need, that is the reason I mentioned an adjustable prop valve. you can adjust the bias so the rear wheels don't skid undert heavy braking
How about stuff like.....
1) Venting rear
2) Flex Lines to Hard lines .....
3) Cleaning calipers/pistons or inspecting them - they have sat like that for 2 years ?
4) Safest/best way to route across the front. Guessing on backside of the XMEMBER ?
to vent the rear axle you can use a stock axle vent bolt that is long enough to go through a stock rear axle brake hose that would normally go from the frame cross member down to the axle. the hose would have a mounting flange on it for that purpose and the bolt is hollow with a barbed fitting on the end so a diff vent hose can be attached. for the hose if you use a stock hose it will be available at any parts store later on in the life of the truck.
this link talks about that and also some otjher ford 8.8 stuff when swapping axles
http://www.fourwheeler.com/how-to/tr...ngler-rearend/
https://www.ebay.com/bhp/axle-vent
flex lines to hard lines
use a bracket welded to the frame (or bolted, whatever. even a hole in the frame flange is common on stock vehicles) to hold the flexible hose and a "C" clip to hold it to the bracket. then the hard line screws into the end of the flex line. look under any vehicle for an idea of how that works. see the pic in the link below and imagine the end of the hose, without the attached bracket, slipping through a hole in the frame of a frame mounted bracket with a hole the size of the fitting o/d, it would bottom out on the C clip attached to the hose already, then on the other side of the bracket another C clip is used to keep the hose from slipping back out of the bracket. the other end of the hose, with the attached bracket, goes to the diff and is held in place with the hollow bolt mentioned above. the hard lines screw into that fitting with the attached bracket and those lines go to each side brake caliper. flex hose like the axle swap pics show in the other link
cleaning calipers etc
plug the brake line hole so no dirt gets inside. if there is already dirt in there simply replace or rebuild the calipers. if they are clean inside the brake fitting hole then plug that and do some cleaning/inspecting. look for a cracked or torn rubber boot, siezed pistons etc. really, if they need work, a rebuilt caliper is pretty cheap compared to resealing the old one and hoping you don't need to buy new pistons etc.
routing the hard line out front
run the hard line across the back side of the ifs member or another cross member that is close. use nice frame clips to hold it securely. terminate the hard lines similar to the rear, with a C clip holding the parts in place