Hey Gary. Since my car has already been painted and I am doing everything backwards, I am leaning towards just painting the bottom black. Was think a 60% gloss. Considering the same for the subframe, firewall & inner fenders.
Research your thinking 60% gloss black Mike as I thought sub-frames, firewall, and underneath were 30% gloss black. That is what I have observed and noted. while many other components were in the 60% gloss black liike the inner fenders and a-arms.
Hey Chick, last time I painted the subframe firewall and inner fenders, SEM Trim Black and I was not crazy about the result. I was told that it is about 30% gloss. However. Having an original paint Z/28 in my garage, shows me that SEM Trim black does not look like the original finishes on this particular car. Even though the paint is 43 years old, it still has a deeper black look and a bit of a sheen.
I am going to try to match the finishes as on the original car.
Her is the original paint on the bottom of my car. It was covered for 43 years with undercoating, and when I removed the undercoating the original paint was revealed. Obviously different light affects how it looks when the picture is taken, so perhaps these pictures are not the best representation. However in person, there is a noticeable difference between all of the finishes. I will take a look at your build thread for a reference.
Here is a picture of what I am thinking of going with on the bottom of my car.
Here is the current finish on my car with SEM Trim Black