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Discussion Starter #1
Are there any modifications or add-on's that should be made to my frame before powder coating? I may autocross this car.
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On first and second generation A body frames, I'd look very close at the passenger side front frame area where it curves downward behind the lower control arm mount. A body frames often crack in this area coming off a welded seam. ESP ones that have had heavy powertrains installed since day 1, lot of miles on them, subjected to much higher HP engines on the strip, then run ragged on thevsteet. I'd weld up any questionable welds.

If the car/frame previously has had a ton of miles, and the frame has been to the frame shop multiple times to be chained down and jacked in order to get it to hold an alignment (for a while), most likely has the MOOG upper arm "crash shafts" in it, it very well may behoove you to start over with a low mile frame, one out of something that hasn't been driven into the ground. What eventually happens in high mile heavy drivetrain '72 and earlier A bodys is the front frame crossmember fatiques. I've ran across the serious frame crossmember fatigue several times on very high mile driver GTO's and a few other A body's with factory installed big block engines.

If you don't mind the extra weight, you can buy one of the frame boxing kits and weld the extra steel plate sections in, not as strong as thevfactory formed HD frames, but it s an improvent in frame rigidity. With such a kit, first, investigate it thoroughly, you may need to look at where your 3/8" fuel line runs and note if any rebending or line replacement is going to be required. I've never welded a hardtop frame up with the aftermarket plate pieces, have only dealt with factory HD frames/ convert frames and center boxed areas; i.e, have even created factory HD/convert frames out of two different A body frames.

Front of the rearend mtg crossmember, you can either continue to run the very late '65-67 "4spd" braces, buy the repro versions, or buy the tubular style offered by several aftermarket companies. Would also box the upper and lower rear control arms. Factory '66 442's actually had boxed upper control arms, have a pair, and the upper rear control arms in my 455HO GT-37 had the exact same boxing installed over 40 years ago. Be careful with the extent of installing polyurethane control arm mounts in the rear suspension. I never install them in the cast upper perches on A body rears, the urethane bushings will create bind, not free movement that is needed at that point.

What are you running for spindles?
 

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Discussion Starter #3
I haven't decided on spindles yet, but they might be a 2" drop. Thanks for the frame info. This car has never been wrecked. I will inspect the frame after sand blasting and before powder coating to check for cracks.
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First off, I'm no engineer or expert on suspensions or frames or anything else you are going to see. I simply did my research, borrowed ideas, did what looked to be best & what would work for my application..........and have my fingers crossed it will work. I have a photo on my profile of the completed set-up and a little better explanation.

I plated and braced the control arm attachment points on my '68 Lemans. Your frame may be different, but you might get a few ideas out of it. Here is the lower control arm attachment at the frame. I didn't feel it was rugged enough to handle big torque & wide sticky tires. I made templates using a manila file folder and then had my local fab shop work me up 1/8" flat plates for the top & bottom. I also had them form the plate on the side where the bolt goes through. (Good way to "tighten" up the bolt hole if it happens to be worn at all). Then I welded it up to tie it all together. All Grade 8 bolts & nuts. I am using the fully adjustable UMI tubular lower control arms. They have the Roto-Joints on each end. I got the ones that can be used with the factory sway bar, but in my set-up, I was unable to use the factory position of the sway bar with the 9" Ford & the 3" lift I put into the rear suspension. Fabricated a little different set-up, but if you are going to lower yours, you should have no problems.
 

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Here are the upper control arm mounts. The factory again looks weak for big power. Made my templates, had my fab shop cut the size I needed, and then I used my template to shape and fit. They go on the outside of the upper control arm tab, which is also about 1/8", so now I have some meat there. Welded it up along the factory tab and up where it meets the upper control arm crossmember. I am using the Spohn adjustable UCA with the "Del-Sphere", EXCEPT, I could not use them as made because I made big changes due to the Ford 9", but you should have no problems here either.
 

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First photo is the front side of the UCA crossmember sand blasted and where the attachment bolts go through.

Now, I also wanted to make the upper control arm crossmember stiffer while adding more support the the side opposite the UCA tabs I beefed up on the back side. Again, did a lot of measuring and made my templates. Had my fab shop bend a 10 gauge piece of plate with the same radius as the factory crossmember so I could lay it on top. I made my cutouts where the factory bolts go through and then welded on my "ears" that lay up against the flat side of the stamping where the bolt goes through. Took some time to fit, shape, & weld the ears. It literally fits over the crossmember. I did not want to weld on the crossmember, so I bolted it up using 3/8" Gade 8 Bolts, Nuts, Washers. It ain't goin' no where and I did not have to worry about warping the crossmember. Secondly, the bolts that go through the "ears" which hold the UCA and keep it in place as well. Very rigid.

You can also see the UMI upper & lower control arm brace which ties them together. You can also see the lower control arm boxing I did. The entire "upgrade" I did to the rear frame/suspension should be good for about 10,000 HP if my slide rule is correct!:laugh2:

I am also using the aftermarket frame rail boxing kit which is essentially a flat plate you fit & weld to the outside of the rails. I started them and had to do more fitting than I liked as they just didn't lay on the frame rail and weren't quite good to go out of the box -but this may just be my application. If you use them, you have to relocate your fuel/brake lines to the outside of the plates as factory puts them inside the side rail channels. My fear is also that you will have to weld them solid and you may wind up warping the frame rail if you don't know what you are doing. So I am rethinking this. Now what I am thinking is that I will set the plates 1/4" or so inside the open channel of the frame rail, thus creating more of an "I-Beam" fit. I am thinking I will bolt my body back down to the frame (using polygraphite body mounts) to get my frame rigid, then stitch weld the plates to keep any warping down. Using it like an "I-Beam" should not require me to weld it up solid like I would have if I placed the plates on the outside due the the very nature if the plate now being inset of the frame channel. At the same time, the 1/4" inset (or so) will allow me to run my fuel/brake lines within that space for a neater look.

Rather than buy the boxing plate kit, looking back, I could have gotten these plates made at my fab shop fitted to my rails and maybe saved some work and a few bucks. Just sayin" :thumbsup:
 

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Discussion Starter #7
Thanks for all your suggestions! I think I will do what you suggested, just make my own plates to weld on the frame to box it in. This isn't rocket science. Just looking at your pictures gives me great ideas as to where and how to brace the important mounting points on the frame.
Thanks again.
 
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