Congratulations on your new Kar, Marshall. It is unclear to me as to what part of the mount is actually hitting your exhaust manifold. After looking at one of my Kars that has 65 style HIPO mounts it seems most likely that your manifold is hitting on the cast iron part. The first things to know about the cast portions of your mounts is that they are standard and not Hipo mounts. I know that it is tough to see the numbers sometimes however your numbers are actually C3DA 6A030 B and C3DA 6C041 B. Note the C3DA rather than the C3OA prefix to the numbers. If you recheck the numbers on your cast brackets, you will be able to see this. The correct HIPO cast brackets have C4ZA numbers. Regardless of having the wrong mount assemblies, the manifold will still not hit on the cast bracket unless the rubber part on the mount has sagged from time. If you had the correct HIPO upper parts of the mounts, your engine would be stting one inch too high as the C4ZA brackets have a lower saddle to accomodate the complex HIPO upper mount assemblies and your problem would be in the opposite direction. This means that you definitely have standard mounts. The rest of the standard mounts that you have are pretty straight forward as there are only two other pieces per side. You will have a stamped steel angle bracket that has a stud sticking down through the cast bracket with a washer and nut on it. The upper part that attaches directly to the block, has a large rubber block molded to it and another stud that attaches this part to the stamped steel bracket with a washer and nut. The problem is with the rubber block as they tend to sag over time. They start off very square in the beginning and become more of a parallelogram over time. This effectively lowers the engine block closer to the cast frame mount. Usually the first sign of the motor getting lower is the fan hitting the shroud. There are two ways to correct this problem if you are going to continue using standard mounts. One is to replace the rubber mount assemblies with Ford only replacements. The reason that I state Ford only is that, in my experience, the aftermarket mounts have a softer rubber and sag some at the moment you put the engines weight on them. I had occasion at one time to be out of one side of genuine Ford mounts so I used a GYPO, non Ford as known in the Ford parts business, mount on the other side. I ended up with the engine noticeably leaning to one side as I set the engine back down on the mounts. The other correction if you do not wish to buy mounts is to use flat washers between the mounts and the block where the bolts go through and the bolts will hold them in place. This will help to compensate for the mount sag. Of course the correct HIPO mount assemblies would also be good to install at this time however they are tough to come by these days and command some pretty good prices. The rubber blocks on the HIPO monnts can also sag creating a similar problem but it takes a lot longer to show up as they are much beefier.
-Fred-