Rear Discs or Rear Diff?

[Pool Fixer]

Adding the Dr Diff rear disc brakes set off a process of chasing perfection that lasted over 16 years. The car just didn’t impress me. I tried numerous changes… multiple manual master cylinders, front caliper sizes, entire front brake swaps, a few power boosters, power master cylinders, proportioning valves and distribution blocks, etc.
Just this year I was able to find a satisfying combination.
My goal was to have the brakes feel and react like a newer car. It sure took a while to get to that point.

I've read a couple of your posts about that... that's quite journey. I have the 13" front cobra kit with the 10.7 rear kit. He sent a prop valve with the front kit but said thats if I was keeping rear drums. He said if im doing 4wheel disc, use factory prop valve. I'll revisit this thread when I'm done, will be a couple of months till pool season slows enough to work on the car.

 

[Kern Dog]

Over the years, I have learned that with a 4 wheel disc system, you don't use a Proportioning valve. The goal is to have Natural proportioning where the caliper sizes are chosen to have a 2 to 1 bias toward the front. Prop valves only reduce brake line pressure so you don't need one unless the rear brakes lock up before the front. Adding a prop valve to a system that either locks up the fronts first or locks up none of the wheels adds nothing, like taking medicine for an ailment that doesn't exist.

 

[Pool Fixer]

I wanted to circle back to this. It started with a choice but this is ‘MERICA , so I did both. My usual ready, fire, aim logical thought sequence. Oh and while your in there, new shocks, add drain plug to the housing, scrape some crud and give the housing a Craig’s list rattle can rebuild, sorry lost the receipts

I’m wrapping it all up and haven’t even bled the brakes yet. Also waiting on a bracket for my ebrake cables. It got lost during a subframe connector install- another truly ‘MERICAN moment. And i can’t believe I’m turning into one of these guys but now I HAVE to remove and wire wheel the exhaust clamps because my new bling blings make that rust really stand out.

 

[Kern Dog]

YOU are a baller, a shot caller. YOU got it done because YOU are the one.
Good for you, man.
If anyone asks WHY?.....
Because AMERICA.

 

[hdwrench]

GV may be in the plans some day... or the silversport 4L60 kit. I'm going to see how it is living with the 3.23's. I've run this car with it's currnet big block on the original 2.94 open diff that was on it from the factory, 3.55 cone type SG with worn out cones, and now tis 3.91 SG that it currently has. I guess it's time to round it out with a set of 3.23's.

still trying to decide to get my OE 2.94 open upgraded locally with new gears and add limited slip or just order a complete one from dr diff or quick performance. OE is a 742 so that's desireable I guess. my 3.91's are a 741 case.

i picked up a2.94 w suregrip locally for cheap . as it’s not a “hot” ratio guy wd getting rid of it . i’d look around for one .

 

[Fran Blacker]

If you haven't decided yet, buy the pumpkin but with 3.55's.
More fun and fairly trip friendly.

 

[Pool Fixer]

d

i picked up a2.94 w suregrip locally for cheap . as it’s not a “hot” ratio guy wd getting rid of it . i’d look around for one .

I have the 742 case 2.94 that the car was born with. I dont' really care about it so maybe that's the one I try my first ever DIY suregrip on.

I run a 28" tall tire and I plugged my info into the RMS speed/rpm calc. Looks like I'll be able to do 70 @2800 rpm. I rarely, if ever, leave long island and speed limits here are still 55. 68-70 is about all you can do and be carefree with zero worries about the man.

As far as I know, my 2.94 open is still good so If I was to get a crazy bug in my *** to do power tour or cruisin the coast, I could put that pumpkin in.

 

[Pool Fixer]

YOU are a baller, a shot caller. YOU got it done because YOU are the one.
Good for you, man.
If anyone asks WHY?.....
Because AMERICA.

F'ing "MURICA Kern Dog!!! Love this place!

 

[Cranky]

d

I have the 742 case 2.94 that the car was born with. I dont' really care about it so maybe that's the one I try my first ever DIY suregrip on.

I run a 28" tall tire and I plugged my info into the RMS speed/rpm calc. Looks like I'll be able to do 70 @2800 rpm. I rarely, if ever, leave long island and speed limits here are still 55. 68-70 is about all you can do and be carefree with zero worries about the man.

As far as I know, my 2.94 open is still good so If I was to get a crazy bug in my *** to do power tour or cruisin the coast, I could put that pumpkin in.

I don't like the new 'Sure Grips' from China.....junk stuff imo. Did one for a member here and it needed some machine work. One of the 'pockets' that gives the bearing puller room to get under the bearing was pretty much non-existent and had to machine it. Not going to remove any bearings? With the 8 3/4 it's not a problem but is sure is on a Dana 60. The bearing fit radii was much larger than the factory's radius on the fits. Not really a problem unless you are using the standard size shims then it's a big problem and the larger shims is a hassle to keep centered once you're above the radius. IE sloppy.

If it were me doing one, I'd look around for an original SG unit be it a clutch plate unit or a cone. Used to keep the cone units for me and sold the plate units because they brought more money because every one wanted the plate style saying they were 'rebuildable' which is true to point. A cone type can be machined to work well again and for years if someone didn't try to make them grab again by pouring on the chili thinking they would lock up again. They won't and will be destroyed beyond repair when that happens. I made a pair of T handles lots of years ago just to check the health of a SG when I used to hit the swap meets.....can't always tell what they are like inside until it's opened up but it let me know if they were real weak. Stick them in until the splines are engaged then step on one, stand it up and grunt on the other T handle.