@AJ messaged me for dimension/measurements on my CMC for the placement of his Nerf Bars and I thought it might apply to a wider audience so, Stand Back! Here we go:
1. I never got my Nerf Bars delivered from CMC. I know......Hard to believe, they were such a quality outfit, but true, so I had a local guy (Hot Rod Charlie, actually) make up a set for me and then had them chromed at Nu-Chrome in Fall River Massachusetts. Wicked costly, but I think that chrome plating will outlast the fiberglass.
Anyway, the key measurement on my Nerf Bar is the size of the mounting bar that goes through the body and attaches to the bumper mounts.
That bar is a piece of 1-3/4" X 1/4" thick steel stock. I didn't get under there to measure how long it is, but IIRC it's about a foot or so to get in to where the inner mounts are.
2. There are a LOT of variables in all of the CMC builds out there, so I found what I think are semi-standard reference points from which to measure and get everything centered and equal left-to-right. Those are the horn grill openings and the tail light openings, because CMC scores the body gel coat to locate them for you, so at least you get those holes in the right place. So, here's a photo of the front of Pearl:
Locating the front Nerf Bars:
Measuring from the bottom of the horn grill opening (which is the same as measuring to the bottom, horizontal edge of the horn grill itself), the top of the Nerf Bar is located 1" down from the bottom of the horn grill, and the outside edge of the Nerf Bar mount is located 3-3/4" inside from the inside vertical edge of the horn grill opening (look through the grill and you'll see the edge of the fiberglass).
The Nerf Bar Mount hole is ∼2-1/4" high and 3/8" wide, so just make the hole 1/4" taller at the top and 1/4" farther down at the bottom than the mounting bar, and about 1/8" wider on both sides.
Bear in mind that the front bumper mounts are attached to the front beam and can be moved left/right up to 2" (and there may be grease fittings on the beam to contend with) - Just be aware that there is some degree of "slop" allowed here.
Locating the rear Nerf Bars:
The locating points to use are the inboard lens screws on the teardrop tail lights. Sorry, I didn't have a quick photo of the rear of the car.
Measuring from the lens screw center, the Nerf bar mount is 5-3/4" down from the screw and 1-3/4" inboard from the screw. Again, the Nerf Bar mount hole is ∼2-1/4" high by 3/8" wide, so just make the hole 1/4" taller at the top and 1/4" farther down at the bottom and that should align with your rear bumper mounts under the car. These are dependent on where you mounted the frame mounts so if you're doing the nerf bar mounting holes first, then no problemo. Making the mount hole 1/2" wide should give you about an 1/8" gap on both sides. You're OK out to 3/16" on either side once you get everything assembled, but 1/8" is golden.
Just for grins, I drew a vertical centerline on the car and the Nerf Bar mounts are both 13-3/8" outboard from the centerline on the rear. I did not do the same on the front (the driving lights get in the way).
You might be able to make the mount holes slightly smaller vertically (for that 1/8" gap all around) but it's not that critical as long as the rubber seal covers the opening. Buy a set of VW bumper mount rubber seals for a 46 - 67 VW sedan (VW part number 111707197A at bugcity.com ) and see how much hole height will work and not be too big for the gaskets. I just trimmed off the back of the gaskets (that part that normally fits through the VW sheet metal and is not appropriate for our 'glass bodies) to make them fit flush to the body and then glue them to the Nerf Bar mounts with clear or black silicon caulk.
Once you get everything looking spiffy and mounted beautifully, most likely they will rattle and vibrate with road vibrations to drive you nuts. The cure for that is to shoot a nice bead of silicon caulk to fill in between the hole in the body and the Nerf Bar Mount, then shoot another 3/16" bead around the mount itself about 3/8" away from the body, then push the rubber seal thingie in to mate between the mounting bar and the body. Once it cures it holds the bar mount from rattling fo'evah!
