460.465USMC's MK4 Build #9890 - Gel Red is Rad. Blue is Better!

[460.465USMC]

Head rest extensions
After reading Fman's suggestion of adding spacers to the headrests to extend them forward, it was a no-brainer for me to do the same. Without the spacers (extensions) there were several inches my head (and passenger's) would travel backward in the unwelcome event of a collision. I went to McMaster and ordered 2.5" aluminum spacers (92510A479) and 3.75" socket head bolts (91251A639).

Here are the head rests with the new 2.5" extensions. The distance between my head and the headrest is now similar to a couple daily drivers I compared.




Side view. I powder coated the spacers black, so they would blend.




Breeze seat brackets
As anyone knows who orders stuff from Breeze the quality and instructions are consistently excellent. I don't have much to add, because the install is pretty straight forward. Here are a few pictures of my install.

The bases and brackets from Mark are supplied in raw steel. So, I scuffed and cleaned them, then coated with black spray paint so they don't rust. The bases are pre-drilled with 1/8" holes (total of 20), and he provides an assortment of 1/8" and 3/16" SS rivets. Since I'm installing mine over carpet with Thermotec underneath, I decided instead to use 5/16" button head SS fasteners, six total.




Here's a view from underneath so you can see there's opportunity to run the screws into some meat, i.e. not just the flimsy 0.040" aluminum floor panel. For two of the six screws I tapped 1/4-20 holes into the 4" chassis tube (about where the blue arrows point). I fastened the four other 5/16" screws (red arrows) with nylon lock nuts. Only two of the 5/16" screws didn't catch good meat, so I used large fender washes to spread the clamping force. Since I had my powder coating stuff out already for the head rest spacers, I powder coated the fender washers so they blend better.




One of the reasons I chose to go with the Breeze seat brackets is they provide about 1.75" of up-tilt at the front. This is designed for leg/thigh support/comfort on the longer drives. The brackets have four positions, for a total of 2.25" of forward/aft adjustment. My seats sit as far back as possible (just shy of touching the rear cockpit wall), and are roughly parallel to the transmission tunnel (not quite touching the tunnel walls).




The bases also come with 3/16" hardboard, which is also supposed to provide better support by not allowing the seat cushion to push down between the seat frame cross bars. At Mark's recommendation, I will treat them with Thompson's water seal before final installation. They are fastened to the cross bar with self-tapping screws.



It's a good feeling to have the seats secured and set. This Roadster is starting to come together. Still plenty left to do, but me thinks there's a light at the end of the tunnel. Maybe have it licensed and on the road for next summer's driving season? Oh, that would be fun!

11/21/22 update: I swapped out the hardboard and installed ABS sheeting instead. Scroll down for discussion/input from those who've installed the hardboard only to find it break once they are licensed and driving. Added picture of ABS installed below.