The "best" available firewall pad is marginal in my opinion. The rubber membrane material used on the originals was soft, pliable and the insulation / padding was a beige-brown. Current firewall pads use a heavy, stiff plastic membrane that can be made to look similar to the original by applying undercoating however the exposed edges of the insulation material is silver-blue with some bright material added in. The hole piecing alignment on the repros is close but no cigar and I've found the gas pedal requires more effort because the linkage is unable to easily compress the membrane. Although I did use an aftermarket pad for my current project, in future I would make my own. Use the original pad to plot and stencil the piercings you require for your application and add correctly colored / thickness insulation readily available on-line. I might start with thin, black pond liner material followed by an application of undercoating to duplicate the original texture. It might even be possible to build undercoating material directly on the insulation layer to create a membrane. Needless to say the aftermarket doesn't currently do a good job on firewall pads.
