Underbody Dimensions

I decided to post a couple of underbody dimension diagrams here so they would be easier to find. I know that some of them have been posted before, but are buried in hard to find threads.

The first one is for 1971s, and is from my 1971 Shop Manual (figure 12), the other one (figure 13) is from a 1972 or 1973, maybe someone can verify from their shop manuals. Most of the dimensions are the same, some are just a few hundredths different, some are more. One I noticed is the rear of the 71s is shown about 2.5 inches lower while the front is about 1/2" higher.

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So I completed the replacement and it was a relative breeze. except for the cleanup prior to installing the new one. I used a sawzall with long metal cutting blades and removed the crossmember leaving the welded flanges only. Then i used a combination of sawzall, grinders, chisels and brute force to remove the remaining flanges. the dynacorn cross member went in perfectly. After drilling holes for welding, simulating the factory spot welds, I used .30 wire, played with my welder settings and went for it. Looks great! and bummer for the next guy who needs to remove this thing. I took many measurements before and after removing the original and I had no deflection at all after I cut it out. The car was level, with the engine in it and on jack stands. Thanks for your advice.

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Carolina_Mountain_Mustangs said:

I took some measurements for a member once under the hood for inner fenders and radiator support. I have attached again. These are not Ford numbers just some reference dims. from a pretty rust free California car.

I did search the net for more dimensions but there does not seem to be any out there.

Every stamping in the unibody has locator holes, tooling holes, that were used to stamp the parts, check the parts and also used in the weld fixtures to locate the parts. A lot of time you can do cross measurement to see if something is square from one tooling hole to another.

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