BBP disc conversion on an early A

[66durgederp]

Has anyone out there done a big bolt pattern disc swap on an early A originally equipped with 9 inch drums, using 73-76 A-body lower ball-joints? or factory early-a ball joints?, 73-76 upper ball joints and control arms, and M-body spindles, rotors, calipers, and caliper brackets? I have access to an entire m-body for free....so im curious as to what all i should yank off this monster to make mine stop better.

 

[grumpuscreature]

Did this on a '66 Valiant but used a '75 Duster donor. With that said, I would get the spindles, caliper brackets, rotors, and calipers off the M body. Also get the prop valve. Used new '73-'76 A body lower ball joints and upper control arms with new ball joints. It all bolted right up and used the '66 lower control arms. Also mounted the calipers to the front and used '73-'76 A body brake hoses with a slight bend in the tubing at the caliper end to aim the hose toward the connector on the frame rail. The hoses were too short without the bend. If you don't want to hassle with that, use hoses for a '76 up Volare/Aspen. If you want a good feeling brake pedal without going to power brakes, get a master cylinder for a '74 Charger with manual disc brakes. It'll bolt right in and works great. The one thing I didn't do but should have was install Moog offset upper control arm bushings. They give you a little more camber adjustment and mine needed another half degree or so. Hope this helps.

 

[porksoda]

Good info there.

Only thing I would like to add is you will probably have to get new dual master cylinder and new brake lines since our cars have a single master cylinder.

 

[BillGrissom]

Many posts on the BBP conversion, and some on using F,M,J spindles. One guy even puts that in his tagline "don't believe the *** that you can't use F,M,J spindles". I recall an article from maybe Rick Ehrenberg on using those spindles. I kind of recall that you can't use an M UCA, so must get one from a 73+ A or a special bushing that adapts the ball joint stud on your SBP UCA for the M spindle. Note that one package of the Moog offset bushings is only 2 bushings, so good for one UCA or you can use just 1 on each UCA (as I did). Also, read posts here on how to install them, which is opposite from the directions in the package, which was for a different problem (side frame bent in from accident). You want to move the fwd side of the UCA as far out as possible and the aft side in, which will move the upper ball joint aft to get more caster for radial tires.

 

[Hell_Fish]

The calipers you choose depend on your setup. If you plan to run a sway bar, you may need to mount the calipers to the rear, which you will just swap your spindles side to side. A body calipers will have the bleeder in a different spot than a Apsen.

 

[66durgederp]

right on guys thank you! its crackedback that had the "dont believe the fmj spindle" hurrah. I read a few threads about it but it was people asking about using them on 67+ a's, i just couldnt find a solid answer for using them on early A's. so thanks gents, that answers most of my questions as to what balljoints to use. i will also be yanking the prop. valve out of this gran fury, and will convert mine to a dual pot master as well.

 

[JDMopar]

If you don't want to have to hunt big ball joint upper control arms, Dr. Diff in Montana is the guy who sells the tapered sleeve to mate the early a ball joint to a big ball joint spindle. Just Google Dr. Diff, he's a great guy to deal with.

 

[66durgederp]

yes!!! ive heard of him, hes only about 50 miles from me!!

 

[66durgederp]

Found the adjustable control arm bushings through O'rei COUGH COUGH* lleys....143.88 for four bushings....i asked him if he had any lipstick so i could at least look pretty before he stuck it to me....sheesus...i also found out they offer adjustable control arms for 73-76 A-bodies....dont even ask about the price for those. However if worse comes to worse i have a fallback plan....and an empty checkbook. haha M-body destruction comes tomorrow! going to yank the spindles, calipers, brackets, hubs, prop valve, brake master and booster (ya never know) posi 8.25 rear diff, including all the 10' drum hardware and goodies, AND the factory 15 inch cop car rims. so stoked!!