Tall Spindle Conversion for 1964-72 A-Bodies

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TALL SPINDLE CONVERSIONS (aftermarket and OEM)

The tall spindle swap for GM A-bodies was conceived in 1987, when H-O racing (under president Ken Crocie) pioneered this. When this swap was performed first, there was a problem with excessive shim packs, and the possibility of the existing A-frame hitting the steering shaft or the headers, especially for big block Chevrolet and 455 Oldsmobile-powered cars. More details are found at the underlined link above. Currently, Malibu Performance has been the sole marketer of the original tall spindle conversion parts. One of the original conceptions behind the tall spindle swap was the availability of parts, since early A-body front disc brake assemblies have been sought after by restorationists, or considered a rare find in wrecking yards.

Global West/Advanced Suspension patented an upper A-frame that allowed the increase in negative camber, in which the A-frame is shorter than the OEM upper arm, and this, in fact, solved the problem with the excessive shim packs.

*Additional information can be found in the 3/00 issue of Car Craft.

The tall spindles are commonly found on 1970-96 GM vehicles, and the vehicle list below, which came with 11 or 12 inch rotors, include the following:

1970-81 F-cars (Camaro/Firebird)
1975-79 Novas (and their BOP siblings)
1973-77 A-bodies (includes A-specials)
1976-79 Cadillac Sevilles (1976 Sevilles came with 11 inch rotors)
1977-96 GM full size (except the Cadillac limosuines). The spindles are 1 1/4" taller than the stock A-car pieces, and this raises the upper control arm angle. The rotors measure either 11 or 12 inches. Below are the parts commonly used with the tall spindles, and GM or a wrecking yard will have the parts for swapping to the tall spindles.

11 inch rotor conversions

If 11 inch rotors are to be used (if anyone desires to reuse the 14 inch rallies with their classic A-bodies), the spindles are available from GM, under P/N 14012595 and 14012596 (LH and RH), in conjunction with the brake rotor, GM P/N 14008640, which is common with 1979-90 full size cars, 1979 Novas (and BOP variants), and 1979-81 Camaro/Firebirds. The longer and wider outer bearing (CR Services BR3/GM 457049) is used. Here's a generic list of the brake rotors:

Bendix #141201
ACDelco #177-725
ACDelco/Durastop #18A57
Guardian #52-60510
Raybestos #5040
Auto Specialty #AR-8200
Wagner #BD60510

The 1970-78 parts are still available, and the spindle P/Ns are 329349 (LH) and 329350 (RH), while the rotor is listed under GM P/N 334348. The 1973-77 GM A-bodies/1975-78 X-cars (Novas, et.al) are a good source for 1970-78 parts, just in case if the parts are discontinued by GM. The best spindles are those from 1977/78 models, since these spindles are lighter, without any loss in strength ("Knuckle Sandwich", HRM, 6/87). If coming across some 1970-77 spindles, keep in mind that the OEM parts are most likely to be discontinued, and here's a generic list (brake rotors) from the aftermarket:

Bendix #141040
ACDelco #177-557
ACDelco/Durastop #18A3
Raybestos #5214
Wagner #BD60259

Note: what holds true for the rotors is that the spindles are mated to their application, and that means 11 inch spindles use 11 inch rotors, whereas 12 inch spindles use 12 inch rotors.

12-inch Rotors/Spindles

The 12-inch rotor/spindle combination are mostly found on the following vehicles:

1977-79 Cadillac Sevilles
1977-96 GM B-cars exc. Cadillac limousines (e.g. Fleetwood 75 - the brake rotor used is the same one used with 1971-96 Chevrolet/GMC 1/2 ton truck/vans (includes G20); some rotors produced after 1991 will have an ABS ring) These spindles use a single piston caliper (GM P/N 18003760 and 18003761), which are compatible with the OEM disc brake master cylinder. The part numbers listed are for 1980-96 GM vehicles. Keep in mind that 15"diameter wheels (or larger) must be used with these spindles, since a 14" wheel will not clear the brake caliper.

3/16/00 update: late 1995 and all 1996 GM B-cars spindles will have different tapers, and the only difference is a 5/8" - 18 thread, instead of the 9/16" - 18 threads. If you end up with a late 1995/1996 steering knuckle, one must purchase the ball joints for 1996 B-cars (the lower ball joints for 1996 B-cars is the same one used with Chevrolet Astro vans and 1977-96 Cadillac limousines), and have the lower joint machined .080" for proper installation.

This is what is needed for the 12-inch rotor conversion: GM manufactures a 12 inch rotor (P/N 18016035), commonly found on 1LE Camaros (1988-92), and this rotor has a 5 x 4.75 bolt pattern. The 1LE brake rotor is also sold as a replacement component through parts houses. Here's the P/Ns for the 1LE rotor, if the GM dealer is a little out of one's price range:

Bendix #141603
ACDelco/Durastop #18A286
Raybestos #5994
Wagner #BD 61967

The matching spindles used are P/N 14012589 and 14012590 (LH and RH), which uses the longer and wider outer wheel bearings listed under GM P/N 457049/CR Services BR3, which are wider and longer than the old bearings traditionally used with the 1964-72 hubs and rotors (CR services P/N A2). The inner bearings (CR Services BR6) are the same on all GM RWDs.
The 1978/79 GM full size 12-inch spindles will also work (because the larger wheel bearing is used), but the 1980-96 parts are common.

The 1977 Cadillac Seville and 1977 GM full size cars of the BOP/C (Buick-Olds-Pontiac-Cadillac) and station wagons made by all of the GM divisions used a spindle that utilized a smaller outer wheel bearing. The rotor measured 12 inches, and a 1LE Camaro rotor will not fit, due to the smaller bearing size. This means that the OEM rotor should be redrilled with the 5 x 4.75 bolt pattern, and the center hub turned when using steel rims. For starters, it's best to pirate the 1978-96 components, since the 1LE rotor fits and functions on the later spindle, instead of remachining a 1977 brake rotor from the salvage yard or parts house.

There are two bolt patterns used with the 11 and 12 inch rotors, and these are the usual characteristics:

The 5 x 4.75 bolt pattern is common with Chevrolets and other mid-sized GM products, and most of the 11 inch rotors use this bolt pattern. Here's a list of GMs with the 5 x 4.75 bolt circle:

1964-88 GM intermediates (A and G-bodies)
1967-present F-cars*
all model year Vettes*
1949-70 and 1977-90 Chevrolet full size passenger cars
1962-79 Chevy II/Nova (includes clones)
1976 Cadillac Seville
1965-70 Chevrolet/GMC full-size vans
1960-69 Corvairs
all post-WWII Jaguars to mid-1990s
1982-present Chevolet S10/GMC S15/Sonoma pickups*

1982 and later vehicles will have metric studs, instead of the 7/16" - 20 studs. The C4 Vette and Fourth Generation F-car will have different backspacing, unlike other GMs.

The 5 x 5 bolt pattern, common with the 12 inch rotor, is used with BOP full size vehicles to 1976, 1971-2002 Chevrolet/GMC pickups and vans (incl. Astro/Safari), 1977-79 Sevilles, and 1977-96 GM Full Size station wagons, police cars, diesel powered vehicles, vehicles with towing packages, and all Cadillac RWDs.

These are the parts needed to install the tall spindles onto a 1964-72 GM A-body, and these parts can be located at an auto parts store like Pep Boys, AutoZone, et.al:

A set of Camaro ball joints are needed, which are (lower) TRW P/N 10277 (Moog K-6145) and (upper) 10268 (Moog K5208).
The lower ball joint (TRW 10277/Moog K-6145) must be turned .080" to fit into the 1964-72 lower A-arm,
The tie rod ends used are TRW ES2033R/Moog ES2033RL (1964-70), and TRW/Moog ES427 (1971-72). The same part #s are the same with the generic McQuay-Norris product line.

Note: the tie rod ends used are originally used with 1975-81 Firebirds and 1973-77 GM A-bodies (Moog ES427R), and the ES2033RL part is originally used with 1978-88 GM A/G intermediates.

If the existing upper arm can be reused, then these are logical alternatives:

*A rebuild with Moog offset control arm shafts, in which excessive shimming is avoided.
*Some portions of the upper control arm might have to be trimmed, if an excessive amount of shims are needed.
*Another way to avoid a thick shim pack is to use lowered springs, about 1 1/2 inches.
*Use the aftermarket upper arms available from Global West of Hotchkis Performance (if anyone ends up with a set of F-car spindles for less than $100 or for free, spend the extra $$$ for the upper A-frames!). When using the upper arms, follow the manufacturer's instructions.

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