Went to take the car for some excercise and found the brake pedal going to the floor. Pulled the rear wheels and found one of the of the brake springs broken and the wheel cylinder a mess. I've been looking forward to the next time I had to do a rear brake job so I could see if I could make some improvements. I don't want to go to disc and I don't want to make any radical upgrades. Those Ceramic shoes from Praise Dyno seem a bit pricey, so I think I'll just go with some quality rivited ones.

So what are peoples thoughts about these changes. If anyone has any experience with any of these changes, I'd like to hear about it.

Stock 69 SS 396, Ft Disc, Rr drum

New Aluminum drums from some 80's GM car. Looking for an exact fit, if possible, don't want to have to drill or grind.

New 15/16" wheel cylinders. I don't think that should throw off the braking balance much, if at all, right?

Using 2 Secondary pads per side for a larger contact area. Not sure what effect that could have though. Has anyone done that?

Thanks for the help.

IMO the 15/16 cylinders would be an improvement. You might need a rear prop valve though.
Crunching the numbers on a 67 vs a 69, you would still have less rear brakes comparatively in cylinder area than the 67 had (less front caliper piston area in 67).

I would not use two secondary shoes per side. There is a reason the short/long design was implemented. I don't know the reason, but i know it works. I've seen results of both longs on one side and both shorts on the other... wish i could remember the exact details, but IIRC the 2 shorts seemed to do more work. I'm betting if it was on the front it would pull to the short shoe side. I would also not use 2 primaries per side though.

why not got for an 11" rear drum kit?
I did and the car will stop on a dime now.
heres a link
http://www.mpbrakes.com/products/product-detail.cfm?product_id=493

I dont know how many options you'll have,because so many people are going to rear disc...I'm one of the people who didnt.I put front dics on mine and kept the rear drums...non-power...because I like the feel of manual brakes,I've owned the car so long that I really do "know" it as a manual brake car,and adding the front disc only really helped it stop on a dime,which is what I wanted.With all of that said,what I did to the rears was a complete overhaul.I even replaced/repaired the backing plates,one major problem with these type drum brakes is the backing plate...over time the point where the shoes ride get a groove worn in them,eventually this groove becomes a bind point which causes uneven braking,puts alot of one sided pressure on the wheel cylinder eventually causing it to leak,etc,etc,etc.If you do a complete rebuild I think you be suprised and happy with the stock braking power it has...and the cost which should be relatively cheap. Remember the rule too at full breaking without a skid,with everything working correctly,the front brakes are absorbing 75% of the brake load in most cases,so I dont know if you would gain all that much by upgading anyway...just my opinion

Forgot to mention, power brakes.

The car has always stopped fine, but then I've never taken it for a high speed run in the mountains. Don't know how much fade it has under heavy braking.

Here's a link to a story I saw a long time ago about these improvements. I really am curious about the long/short shoes and why they did that though. But you're probably right...it must have been done for a reason.

http://www.chevyhiperformance.com/techarticles/49418_cheap_street_brakes/

The reason they use long and short shoes is b/c drums are self energizing so the shorter shoe energizes about as much as the long shoe does un-energized!

Think of it as the drum twisting and wedging the short shoe tighter and not the long shoe b/c of the way it rotates as it stops and you will see what I mean.. The long shoe actually kinda unloads if you look closely and that's why just pressure alone make's it work.

There have been drums made that had a one-sided cylinder on both the top and the bottom that energized BOTH shoes the same, as well as some that work like ours that although both shoes float, the leading or short shoe does most of the energizing..

And I wanted to install the spindles off the '65, 375hp/396, Z-16 Chevelle b/c it is the ONLY A/F/X car that had 11" drums all the way around but I have NEVER found out what was done to the big car spindles to get them to fit on our cars!!

pdq67

Its called Positive servo effect and negative servo effect.

Positive servo effect is the result of the action of the applied shoe is implemented by the rotation of the drum its rubbing against. It takes less pressure to apply the shoe because the drum rotation is 'with' the application of the shoe. The two vectors add, and the resultant brake force is greater.

Negative servo effect is the opposite. More applied pressure is needed on the shoe because of the drum rotation is opposite of the shoe application direction.

Hence, this is a reason why the primary shoe lining is shorter than the secondary shoe, by design.

The front brakes do most of the breaking (true depending on valving). The rears (I remember) the whole assembly shifts depending on direction of the drum, wedging it. The smaller front shoe is smaller b/c the speed in reverse is usualy not as fast and dosent require as much surface. (they both get used in both directions but very little) Useing the original type shoes ( not metalic or ceramic) is best b/c they dont require it to heat up a little to actualy create friction, so they stop best but wear fast. The stock set up works great!