They made a HUGE difference in heat. I can't say exactly how much since my digital temp gauge only goes up to 160 F, but before I installed them, my digital temp gauge which is mounted to the top of my airfilter would read "888.8" (which means over 160). After installing the louvers, it would sometimes drop into the 150s but would also stay at 888.8 as well (so it was closer to 160 and would sometimes fall below 160), and then once I installed the home theater fans to each louver, now the temps are usually between 140-160 F. Of course it depends on the temp, but generally speaking this is summer time wheeling in the 80s-90s and it only goes above 160 if the truck is sitting still in direct sunlight.
The louvers are a wrecking yard special from a late 1980s Chrysler Lebaron GT, like a 1988 or 89. I've seen em with single louvers and dual louvers. The one I found had dual louvers. Here is a pic I found on Google of a 1989 GT:
I can't take credit for them though, I got the tip from Ruggedjeep here:
http://board.marlincrawler.com/index.php?topic=11671.msg271303#msg271303and here is the install of the vents and the 5" fans:
https://board.marlincrawler.com/index.php?topic=46211.msg580957#msg580957Thanks
Mike
