CHASIS COMPONENT ASSEMBLY

This article will talk about running the fuel lines, brake lines and other chassis mounted items including steering box and steering components. Mentioned in earlier articles, I am converting from 1970 stock 11” disc brakes to the GM B-body 12” front disc brakes, Also known as the “tall” spindle conversion. This applies to 64-72 A-bodies. There is a lot of information available on this conversion, but I will describe what I did. It is slightly different then you may find elsewhere. With the front and rear suspension and brakes mounted, it is time to assemble any rolling chassis components. I purchased stainless steel brake line and fuel lines from the Right Stuff www.getdiscbrakes.com. This is an el Camino frame being used on a Wagon, so the fuel lines need to be for an el Camino. But before selecting lines, another thing to keep in mind and take advantage of the opportunity to change, is the location of the proportioning valve. The stock valve is mounted on the frame close to the exhaust. This normally is not a problem however, when using headers, heat can cause problems to the valve. The right stuff has brake line kits that relocates the valve to up under the master cylinder. I used the stainless front brake line kit CKT68DC, front to rear lines CIN69DC, rear flex hose FH06, rear 2 piece lines CRA6803 SS and stainless brake line clips CC5020. From the 2 piece rear end lines I will run 2 rubber hoses to the rear calipers. The rear flex hose mounts to the 12 bolt rear with a bracket. I blasted and painted mine, but you can now buy reproduction brackets from The Right Stuff. There is one brake line clamp that they do not remake so you need to use your original. It is the long clamp right behind the rear lower control arm mounting location on the driver’s side of the frame. The same applies to the fuel line on the other side, but I will talk about that separately. The brake lines come folded and require some unbending and massaging to fit, but work well. I also purchased but have not mounted until I get the body back on, the 4-wheel disc brake proportioning valve PV72, mounting bracket PVB71, master cylinder DBMC01 and a 9” vacuum booster with rod and bracket DBPB01. One tip is, I found that stainless 1/4” hex socket head cap screws with lock washers work really well on the line retaining clamps to the frame. The hex head bolts had trouble clearing the clamps and some instances, did not work at all.
The fuel line I purchased was 3/8” diameter stainless steel for 1970 el Camino CG171E3 and mounted with stainless clamps CC5018. Same as above, one of the rear clamps will need to be reused. Socket head cap screws were also needed. All the lines come with the spring like stone guards and the fuel line comes with the sleeve that protects the line when it passes thru the front cross member. Because this line is made for an elky, and lines are not made for wagons, this line needs to be custom bent from the rear cross member back. Even if they made wagon lines they would not have worked because of the differences in using the elky frame. The fuel tank of an elky, connects to the fuel lines on the passenger side, but a wagon runs the line way over and back on the drivers side. So finishing the line back still remains. Also I am not sure how I am going to need to set it up for the fuel injection. I might need to run a fuel return line.
Another component to put on is the motor to frame mounts. Actually this is best done before mounting the lower front control arms. You will have better access. I used polyurethane motor mounts for the 454 big block. Mount using grade 8 hardware.
The motor mounts are shown here as well as the KYB shocks which I added to all 4 corners. Also I used a poly-urethane trans mount. I consider the Oldsmobile cross member to be an up grade over the Chevy cross member so I chose to use it. In the picture the cross member on the left is the Chevy cross member and the one on the right is the Olds. One thing to note it that the cross members in convertibles and el Caminos are 4 to 6 inches shorter then the cross members in 2-door and 4 –door cars and wagons. This cross member came from a cutlass convertible; it will fit this elky frame just fine. The olds member is made from thicker steel and does not have a closed interior which can hide rust, like the Chevy member. Either one works.
To add to the already stiff frame and wagon body I also choose to use poly-urethane body mounts. I purchased the set from NPD National Parts Depo. 800-874-7595, they come complete with all the inner sleeves, washers and hardware. They also included the radiator support mounts. Moving along to the steering box, I decided to get rid of the 1970 steering box (14:1) for the 83-88 Monte Carlo SS (12.7:1) steering ratio. Pre-1970 cars had an even worse steering ratio, getting as bad as 20:1. This change will increase your steering dramatically. You can buy a kit for $65 from Tom at Lee Manufacturing 818-768-0371. The kit has 2 hose fitting adapters and the correct rag joint connector. With those three pieces it is a direct bolt on. You use your pitman arm, power steering hoses and steering column shaft. A common misconception is when people try to figure out what their steering ratio is by counting the number of turns of the steering wheel from lock to lock. Lock to lock meaning turning the steering wheel till it stops from one direction to the other. This is not accurate at all due to the fact that there are stops built into gear boxes which can stop the travel of the steering in different places varying from one gear box to another.
Also there are steering travel limiting stops on the steering arm which hit the lower control arms before the tire rubs the inner wheel well. So the only way to be sure of what you have or verify what you may have just bought and think you have, is to do as follows. I have drawn up this geometry below. Print it and blow it up until the size of the dash lined rectangles are the (8.5 x 11) size of a sheet of paper. It will require 2 pieces of paper it fit the entire picture. Tape the paper to a board or like I did a piece of 1/8” thick aluminum. Cut the .438 diameter hole out to fit over the steering box shaft. You can see the 10 and 1 degree deviations on the paper.
Tip: The pitman arm nut is 1-5/16”. Tighten the plate down sit the steering box down somewhere sturdy. Position a wire, like shown, at the first vertical line on the paper while the steering box is all the way to one end of its travel by turning the rag joint. Position another wire on the rag joint bolt and point it to a place on the gear box and mark where it points. Turn the rag joint 2 full and accurate turns and count the number of degrees the wire on the paper has indicated. I turned 2 turns just to help with the accuracy. You would be surprised how close it is between 14:1 and 12.7:1. The stock 1970 box should turn 51.4 degrees with 2 turns of the rag joint. That means 25.7 degrees per turn. Divide 360 degrees by 25.7 and you get 14. That is the 14:1 gear ratio. The Monte SS box should turn 56.69 degrees with 2 turns of the rag joint. That means 28.3 degrees per turn. Divide 360 degrees by 28.3 and you get 12.7. That’s the 12.7:1 “quick” gear ratio. I got my steering box at Napa for $153 with a core return. Part number 27-6550. You can see by the above numbers that there is very little difference between 51.4 degrees and 56.7, so it is real important that you take this measurement carefully.
Be careful! I bought a used box from a Monte SS, but when I check it, it was not the quick ratio. Somewhere along the life of that Monte, someone replaced the steering box on it with a regular Monte Carlo steering box. The factory steering boxes stamped the quick ratio boxes with a yellow ink “YA” but this wears off very easily just by wiping it. Saginaw also made some variable ratio gears in that time frame. Contrary to what you would think, these gears had a slow ratio (higher number) right over center and a faster ratio at near full lock. The ratios were 16-13:1 and 15-13:1. Some variable ratio gears in 1969 and 1970 were listed as 16-12.4:1. These gears effectively reduced the number of turns lock to lock, but they were dogs over center. My purpose for this information is that if all you do is check for steering ratio at full lock and back, you might think that you have a gear with a fast overall ratio rather than one that varies from on center to full lock. So to be sure, you should check the ratio either side of dead center as well as the ratio at near full lock. This will provide the most information on your gear ratio. A-body cars had variable ratio gears in the following years: 1969 code AU; 1970 codes BA,CF; 1971-2 codes CA,CL; 1973 codes GA, JT, WU, XA, XB, WZ; 1974 codes EP, GD, ER, and more.
Use a ¼” bolt as a punch to seat the 2 adapters the kit supplies. They just get pushed in until they bottom out in the hose fitting ports. Now your original lines will seal right in. the thread difference is so minor that your line ends will still thread right in and seal.
Take all the ratio measuring tools off the box and bolt it up to your frame using (3) 7/16-14 x 4.5”long bolts to 64 ft-lbs. The pitman arm is keyed so it is easy to put on. Tighten up the pitman arm nut to 180 ft-lbs. This box has slightly less travel for the steering from side to side. But in my case it is a good thing. The B-body spindles I added (mentioned in earlier articles) limited the travel a little anyway and with the wide tires I am planning on putting on the front, the slight reduction in steering travel will be just perfect to keep the tires from rubbing the inner fender wells.
Bolt up the Idler arm, center link and tie rod ends with the proper torques listed below. I use the Edelbrock Heavy-Duty tie rod sleeves. These are mad of steel not aluminum like others make. There are 2 sizes. 70 and earlier used the smaller 5/8”, where as the 71-72 use the larger 11/16” threads to match up with the tie rod threads. The 5/8” ones are p/n: 350-5250 at Jeg’s for $36.99/pr.
Steering Component Torque Settings
Steering Gear Box Bolts - 64 lb-ft LH/RH Steering Linkage Outer Tie Rod Nut - 35 lb-ft LH/RH Steering Linkage Inner Tie Rod Nut - 35 lb-ft Steering Linkage Relay Rod to Pitman Arm Nut - 35 lb-ft Steering Linkage Relay Rod to Steering Linkage Idler Arm Nut - 35 lb-ft Idler Mounting to Frame Bolts - 60 lb-ft Pitman Arm Big Nut - 180 lb-ft
Well, that’s it for the rolling chassis for now. There are a few things left to add, but I will be focusing on the body for the next article. I have collected some 69 4 door hardtops to convert my 70 wagon sedan into a 4 door wagon hardtop. Stand by!
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