A153 ssbc conversion?

[340CUDA69]

Looks like the best option for my needs but still have a few questions?
69 barracuda with factory 10" POWER drum brakes AND small bolt pattern.
I have been very happy with my factory set up- the old story don't mess with it if it works.
My car has a well built 340 and a big cam and the associated "low" vacuum issue. I added a vacuum reserve canister and worked great to date. Well the booster finally crapped out and would require a rebuild.
I want to retain my small bolt pattern 15" cragars-good
1) does the kit come with the adjustable proportioning valve?
2) my biggest concern? I want to "eliminate" the booster entirely and go to manual disc brakes as supplied in the kit. Will this kit bolt directly to my firewall or are modifications/other parts necessary to install a manual disc kit on a factory power drum car??
I really don't have the required vacuum for proper booster function l believe and have been very happy with manual disc on my previous mopars.
Kits are expensive but straight forward compared to scouring for used/rebuildable Kelsey/Hayes alternative.
Thanks for your input

 

[AJ/FormS]

I had a Purple 292/.509 and I had lots of boost.I measured that cam at 239*@.050. I know, not that big, but about as big as most would think to use on the street with a stick car. Just how big is your set-up?
-When you switch to discs, you will lose the self-energizing feature of drum brakes. This will require you to muscle the brake pedal harder to achieve the same pre-swap stopping distances. This is why most non-sub-compact cars usually come with boosters.
-If you want to keep the sbp on the front(I did), I highly recommend(for streeters at least) the original KH 4-piston set-up.They provide; lots of stopping power,moderate pedal pressure,easy modulation, esp with the 15/16s M/C, trouble-free operation,100% Chrysler engineered to fit, and the compact booster works surprisingly well. And besides that, its cool to say you have Kelsey Hays brakes.
-BTW; what non-boosted disc-brake, 3200lbs plus, Mopar cars, have you owned?
-Also, if you are a hard-charger, or a late-braker, or just generally depend heavily on your brakes, the firewall may need to be braced at the M/C area to resist the flexing that the extra pedal pressure, now required, will cause.
-I also highly recommend the non-rubber type of flex-hoses. The teflon lined ones. Great pedal feel and long lasting.

 

[Darter6]

I used that kit on my 64 Dart build.(See below) Yes it comes with the adjustable prop valve, Yes it is both small and large bolt pattern, remove the studs that won't be used.The wheels I used were 15'' cheappies and didn't clear the caliper.Had to install 3/16'' spacers. Cragars should be ok. Going from power to manual you have to get the mopar adjustable master cylinder to brake pedal push rod.That will be the only extra part you should need.

 

[340CUDA69]

thanks for the response. I actually am running a smaller purple shaft. 484/284 to retain stock rocker gear. I am happy with power brakes. Factory 7" dual diaphragm booster. My brakes all of a sudden got hard. believe l need the booster overhauled. Company in stoney creek Ontario quoted me $400 plus tax to rebuild booster. 727 auto in gear, only getting 8" vacuum. My car is in storage till spring so just thinking what are my options.
My dart l swapped 20 years ago from drums to k/h manual discs worked great. Want to keep sbp and my 15"cragars. Always had small block 3000 lb.a-bodies.

 

[doug 371]

the manual master cylinder will just bolt to where u remove the booster from...all u need is a different pedal to master pushrod

 

[BillGrissom]

A whopping $985 at Summit. The A153 kit uses Kelsey-Hayes calipers, but apparently a custom integral rotor/hub. I don't see a price for the new rotors you will eventually need. I hope not priced like ink-jet cartridges. The MC is an old cast-iron factory one if you like that look (rusty) and weight. They don't state the bore. A 7/8"D would give a workable pedal without too much travel (if no air bubbles and good hoses).

If you get a manual brake rod from a 69 Dart (someone here), it should fit their MC since they say the kit works on power or manual cars. You will need a new rubber bushing for the end.

Since happy with your 10" drums, why not install another booster, the cheap way. I have a booster/MC from a 95-99 Breeze w/ ABS on my 65 Dart (~$25 junkyard). Look at my avatar. I had to elongate the Dart bracket's holes slightly and use dual nuts, but that was simple. I used 1974 Dart firewall brackets, which could vary from your 1969's. Probably many other boosters would work, I just tried the closest car.

 

[340CUDA69]

thanks for all your responses.

 

[340CUDA69]

thanks for all your responses.
I was aware a different length rod was required on the disc conversion.
If l decide to replace my factory 7" dual diaphram booster (I believe it was made by midland according to the service manual-- are these available or is rebuilding mine the only option? I have seen combination master/booster with brackets available which look similar but again claim to require modification to work on factory power brake cars. I believe a template would be provided. Last thing l want to do is modify my firewall to work.
Everything being sold these days seems so vague on fitament and specifics.
thank god this site is available to help us out.
Being up here in Canada does not help much. Exchange rates/duties/brokerage/shipping certainly add up.

 

[AJ/FormS]

-With my purple 292/.509 cam, I had around 10 inches vacuum at around 750/800 rpm,and IIRC around 16* idle advance and 11.1 true C/R.I did not need the vacuum reservoir, though I contemplated it during the planning stages.
-If you have only 11 inches with the 284 cam, I suspect that you may not have enough initial timing, or your C/R is not as high as mine, or your trying to idle it too slow.I know they sound great at lower rpms and with late timing,but I worry about my cam lobes so idle mine closer to 800 for a tad more oil.It seems to be working. My engine has 125,000 miles on it with maybe 100,000 of those with the current Hughes 230*cam and their spring kit,Which I shimmed up for a little more security at 7200 rpm.
-My Midland has always worked great.I chose it over several other types in my stash because of its rebuildable feature, its compact dimensions, its period correctness and, its handsome good looks. It has worked flawlessly for nearly 15 yrs.
-I installed a combination P-valve from a 73 Dart.Later, when I fit 295s out back, I found a bit more braking power by gutting the valve, leaving the brake warning system alone, and swapping out the wheel cylinders out for 1 size smaller.The car stops awesome; easy to modulate, powerful, and has been 100% reliable. I think in day to day, around town, sub 40 mph,that the back is actually doing a lot of the work, as it wears the shoes faster than the pads. But since it has no tendency to spin under very hard braking and, hauls the car down really well, Im not touching it. I had purchased an adjustable P-valve early into the project, thinking that I would absolutely need it. Its still on the shelf in its bubble pack.
-I had to narrow the rear to fit the commonly available 4.5 backspace wheels.I had to move the springs over with the 3/4 inch offset kit,and moved the rear back another 1/2 inch to fit 325/50-15s for track days.
-One summer,I put some sticky 245/50-15s on the front. That was a fun 8 wks until I wore the treads right off those babys. Can you imagine that? They were some soft tires.The next month I put the 235/70 14s back on. The fun-factor was too pricey for me.
-Ah the memories.