Finally threw in some LEDs with varying results. The LED bulb that fits the Chevy truck underhood lite isn't really any brighter than the incandescent it replaced (because its size limited), and is probably not as reliable in this super HOT location - we'll see! An LED in the backup lite helped, the ones in the footwell fixtures that were purchased more or less by accident didn't improve anything, but at least shouldn't toast the lenses as I had to replace one of those as well.
BUT - the "BeamTech" H4 LED replacement bulbs in the e-code Hellas are significantly brighter, even in daylite! I have yet to try them at nite though - in fact, I haven't driven the Jeep at nite since I bought it. I think I'll like the whiter output. Unfortunately, the BeamTechs won't fit in my e-code Hellas on my old MBZ due to a backshell.
I did note a tiny amount of RFI on the AM band with the BeamTechs - although I had to listen carefully. I contacted them for their RFI filter - I don't want them to mess with my eventual CB installation, and might as well try to filter out the broadcast band AM as well. Yes, I *do* listen to AM from time to time!