GM metric chassis

[GPster]

Just asking some quick questions. As near as I can measure the tread width of  a GM metric chassis seems to be about 59" (outside of hub to outside of hub. Is this close? Isn't the wheel bolt pattern 4 3/4" X 5 ? and that would mean that S10 4x4 wheels with negative offset  would bolt on and tuck the wheels in more? I asked an expert if he knew of a site with frame dimensions but he's getting his information out of a GM shop manual and my library doesn't have any so I'm getting mine with a tape measure while walking the dogs and looking at a stripped chassis about ready to be dirt-tracked. Here's the story. My name (GPster) comes from the fact that I have one (Jeepster) and I'm now playing with the idea of putting a newer chassis under it. All the mini-truck chassis have leaf spring rears and for my purpose the Metric coil-spring rear end would be better suited. If I start looking this is '78 to '86 right? GPster

[tomslik]

Just asking some quick questions. As near as I can measure the tread width of  a GM metric chassis seems to be about 59" (outside of hub to outside of hub. Is this close? Isn't the wheel bolt pattern 4 3/4" X 5 ? and that would mean that S10 4x4 wheels with negative offset  would bolt on and tuck the wheels in more? I asked an expert if he knew of a site with frame dimensions but he's getting his information out of a GM shop manual and my library doesn't have any so I'm getting mine with a tape measure while walking the dogs and looking at a stripped chassis about ready to be dirt-tracked. Here's the story. My name (GPster) comes from the fact that I have one (Jeepster) and I'm now playing with the idea of putting a newer chassis under it. All the mini-truck chassis have leaf spring rears and for my purpose the Metric coil-spring rear end would be better suited. If I start looking this is '78 to '86 right? GPster

there was something goofy about 78 spindles(as far asdropped spindles, and it's 78-87

[1FATGMC]

I thought my 78 Buick Century was a G body, but when Frank was here he said it is an A body, but the same basic dimensions (Frank correct me if I'm wrong).  

If that is so then you have more models to choose from.  I also have an '84 Chevy caprice wagon here and he said the spindles from it would work on the metric front for better (bigger) brakes.

Of course you probably already knew all of this.

c ya, Sum

[enjenjo]

To go back over it, A bodies, Lemans, Malibu, Special, and Cutlass from 78 to when each division went to front wheel drive, G bodies, Grand Prix, Monte, Cutlass Supreme, and Regal, all used the same frame with some variations in wheelbase. All the A bodies, G bodies S10/15, and small bolt pattern big cars used the same spindle. F bodies, Camaro, and Firebird 70 to 82, A bodies, and G bodies, 73 to 77, and X bodies, Nova and clones, 75 to 79 used the same spindle. The B bodies,Impala , Caprice, Cadillac Deville, Bonneville, Parisiene, Olds Royale, and 88 with a 5" bolt pattern used a spindle with the same dimentions as the F body spindle, but set up for 12" brakes instead of 11" brakes, from 71 to 96. This spindle is a direct bolt on to replace the F body type spindle, but you have to use 94 Camaro 12" rotors to keep the 4 3/4" pattern on the wheels. It will also bolt in place of the 78 to 87 A and G body spindle, but the upper A frame becomes too long, and must be shimmed back some more, about 1/2".

The 78 Spindle used different bearings, and the brake rotor has Imperial studs instead of Metric, but will interchange with the later stuff as assemblies.

[1FATGMC]

A bodies, Lemans, Malibu, Special, and Cutlass from 78 to when each division went to front wheel drive, G bodies, Grand Prix, Monte, Cutlass Supreme, and Regal, all used the same frame with some variations in wheelbase.

All the A bodies, G bodies S10/15, and small bolt pattern big cars used the same spindle.

F bodies, Camaro, and Firebird 70 to 82, A bodies, and G bodies, 73 to 77, and X bodies, Nova and clones, 75 to 79 used the same spindle.

Trying to get this straight before I print it out and save it.  Was the spindle on the F bodies above different than the A/G bodies???  I think you are saying they are, but I just want to make sure.  

Is the small bolt pattern 5 on 4 3/4 and the large 5 on 5???

The B bodies,Impala , Caprice, Cadillac Deville, Bonneville, Parisiene, Olds Royale, and 88 with a 5" bolt pattern used a spindle with the same dimentions as the F body spindle, but set up for 12" brakes instead of 11" brakes, from 71 to 96. This spindle is a direct bolt on to replace the F body type spindle, but you have to use 94 Camaro 12" rotors to keep the 4 3/4" pattern on the wheels.

So these spindles will bolt on to the F bodys mentioned above and "will not have to be shimmed".  Correct or not???

If you use the spindles on the A/G/S10's then the A frames have to be shimmed???

Also to get the 12" rotors and 4 3/4 bolt circle you can only use the one year of Camaro -- 1994???

Will these rotors clear 14 inch wheels???

How will using the later spindles and the '94 Camaro rotors effect the track width of the A/G/S10's???

I'm sure for everyone else your post was perfectly clear, but have pity on me.  I did take you and your wife out on an easy day trip  :oops: .

c ya and thanks Frank,

Sum

[enjenjo]

From 73 to 77 A, G, and F bodies used the same spindles, from 78 to 87, the A, and G bodies used a different spindle than the F bodies

The B body spindles will bolt on to a 70 to 82 F body and a 73 to 77 A and G body, but have to be shimmed for 78 to 87 a and G bodies

94 Camaro was the only one that had 12" brake rotors with a 4 3/4" pattern. Actually there is another one, but it was rare, and is no longer serviced, so I won't even tell you what it was.

Small bolt pattern is 5 on 4 3/4", large is 5 on 5". there is also a bolt on 4 1/2"  rotor that will fit the GM 12" spindle, 71 Mercury full size fits, and has a 4 1/2" bolt pattern. Use the stock GM inner bearing, and a 94 Camaro outer bearing.


When using the B body spindles, or the F body spindles on a 78 to 87 A or G body, or any S10, you have to shim the inner shaft of the upper a frame, more than stock by about 1/2". This is where the stock alignment shims fit. I just use a washer 1/2" thick, and do the balance with stock type shims. there are a couple companies making shorter upper A frames for this conversion too, Global West comes to mind.

The 12" rotors will not fit 14" wheels, not at all. you can get around this by using +1 sizing on the tires. If you are running a 225 60 14, change to a 225 50 15 for roughly the same overall diameter.

Using the F body spindles makes the track about 1" wider overall. The stock trad width on an A or G body 78 to 87, is just about 56.5 inches, the S10 tread width is 54" the tread width on a stock 70 to 82 F body is 60.5 to 61" depending on the particular application.

S10 4x4 wheels will fit either the AGS spindles, or the F body spindles, and will narrow the tread 4" overall. 78 to 85 Toronado, Eldorado, and Riviera use the same wheels as a S10 4x4. 84 up Corvette C3 wheels will work too for nearly 6" narrower tread overall.

[GPster]

Another look at the racecar in progress still hasn't killed the idea. Between the wheels the straight sections of frame are 56" apart . The Jeepster body is 50" wide at the floor on the firewall end but is probably real close to 56" wide at the rear wheel wells. The Jeepster wheelbase is 104" so the frame would have to be shortened. Maybe I could re-make the front frame kick-outs to not go as wide (50") and bring the shortened rails into these re-made kick-outs so that the side rails are no longer paralell but form a trapizoid. There is no floor in this body or running boards and the bottom edges of the body that covered the sides of the frame are gone. This would allow me to mount the body on top of the sides of the frame rails like a '32 Ford and let the height of the frame substitute for the missing height of the body. It's been so long since I've thought about this project that anything feels incouraging. GPster

[GPster]

First, a point that was missed. The width  of the axel set-ups is about 59"? Yes? Looking at the models that used the "A" chassis or the "G" chassis the main differance seems to be family car or sporty 2 dr. sedan so I figure that the "G" chassis might be heavier to prevent body bend on the more stylish models. Do you think this difference is enough to worry about when I shorten the wheelbase to 104" and put a light convertable (actually a roadster) body on it with no back seat and minimal overhang?  GPster

[1FATGMC]

First, a point that was missed. The width  of the axel set-ups is about 59"? Yes? Looking at the models that used the "A" chassis or the "G" chassis the main differance seems to be family car or sporty 2 dr. sedan so I figure that the "G" chassis might be heavier to prevent body bend on the more stylish models. Do you think this difference is enough to worry about when I shorten the wheelbase to 104" and put a light convertable (actually a roadster) body on it with no back seat and minimal overhang?  GPster

Your question??  I don't know, but if I used one of these front ends I would cut it off of the frame between the firewall and front a-arms and make the frame from the firewall back from .120 X 2 X 4 square tubing and make the crossmembers.  I actually think it would be easier and faster than working around the existing frame members on the car body.

Or cut it off like I mentioned abouve and install it like a Camaro sub-frame with your existing frame rails and maybe box them in it needed.

Frank thanks for the additional information on the different components and years.  I think I have it now.

c ya, Sum

[GPster]

if I used one of these front ends I would cut it off of the frame between the firewall and front a-arms and make the frame from the firewall back from .120 X 2 X 4 square tubing and make the crossmembers.  I actually think it would be easier and faster than working around the existing frame members on the car body.
Or cut it off like I mentioned abouve and install it like a Camaro sub-frame with your existing frame rails and maybe box them in it needed.
Sum

I did what you suggested one time to a Chevelle frame for a '38 Lincoln that had been cut down to make a truck cab. It worked well but I don't see it for this. Like I said I'd like the frame to form the lower/outer edge of the body between the wheels. When I said that there was no floor I mean supports and crossmembers either. This body consists of a cowl with a firewall, 2 doors, two quarter panels with some of the rear fenders and the body's bustle with the spare tire mount and the convertable top mechanism. The original frame is of "top hat" construction like the earlier than '55 chevys and the bottom of the frame is gone. I put a dropped tube axel and dual leaf springs under the front and a '66 mustang 8" under the back. Tube crossmember with motor mounts and Vega steering box set-up for cross-steer. With this thing sitting outside for 2 years, under water twice last year during both floods and my mood being on the bottom I thought maybe I should try another tack. GPster

[Ralph]

All this talk about spindles has me thinking again. In my case I have a 79 Camaro clip under my 40 Plymouth. WZ Junk was trying to remember a way to narrow it. Can I narrow the track 1/2 inch per side by using B body spindles, and 94 Camaro rotors? I'm still looking for a way to narrow this thing at least an inch. An inch (or more)per side would be better. I'm looking at narrowed A arms at the moment.
Ralph

[1FATGMC]

Like I said I'd like the frame to form the lower/outer edge of the body between the wheels. When I said that there was no floor I mean supports and crossmembers either. This body consists of a cowl with a firewall, 2 doors, two quarter panels with some of the rear fenders and the body's bustle with the spare tire mount and the convertable top mechanism.

With what you have to work with it seems to me that you would have to get real lucky to have the car frame fit the body sides like you want.  I think it would be much easier to use the front clip and come back along the body with the square tubing and make cross members.  It is like a house, it is much easier and faster to build new one than to go in and re-model or have to attach to and existing house with an addition.

I put an all new floor in my truck and it went much faster than trying to work with the old one.  Make main crossmembers for the frame and make floor members out of 1 X 1 thin wall square tubing and weld 16 gauge to that.  Pretty quick and simple.  Doing this you are dealing with all square sided materials and not some factory frame that curves every which way.

Just my thoughts,

Sum

[enjenjo]

All this talk about spindles has me thinking again. In my case I have a 79 Camaro clip under my 40 Plymouth. WZ Junk was trying to remember a way to narrow it. Can I narrow the track 1/2 inch per side by using B body spindles, and 94 Camaro rotors? I'm still looking for a way to narrow this thing at least an inch. An inch (or more)per side would be better. I'm looking at narrowed A arms at the moment.
Ralph

No. Outside of the rotor diameter, and the caliper mount, the spindles measure the same.

[Ralph]

Thanks Enjenjo. It could never be that simple, could it. Rats.
Ralph

[GPster]

Talked to a man that puts together "Dirt Track" car frames for clients around here. Has for years. He uses the metric frame and has for years. He mentioned the tread (wheel mount to wheel mount) width to be 58". He suggested I visit a body shop that does frame work to get the dimension lay-out that I want. He speaks highly of the frame although he admits that the condition of the frames in this area of the country is kind of "flakey" (rust). For others information he has found that the spindle and hub difference listed for '78 has hit him with the'79s and goes either way with the '80s. Even though the interchange books list them as the same he stays with the '81s and newer so that he is sure of like pieces. Still working on this idea But with 2 days of sunlight and warm temperatures to stock frame is not looking as bad. GPster