I’m sure Brian Wilhelm will chime in, but I believe he runs MCP/Enginetics equipment on his kart. I’m building a 150cc clutch kart to run Unlimited and possibly F-125 if I can carry enough methanol, and I’m using MCP/Enginetics on mine and have been getting some help from Brian. Some of it is the same equipment I used on my TaG-Enduro kart I built in 2008. That kart was fast and heavy (anything with me in the seat is heavy) and it stopped fine.
I just bought a nice 7-1/8″ vented rotor from Brian (made by Terry Ives) that bolts to standard MCP 4-bolt brake hub for 1-1/4″ axles. I’m using an MCP billet rear caliper that has 1-1/2″ pistons (don’t think they make this one any more). On the front I’m using Enginetics EC-750 single piston caliper. This is the large caliper that has a 1-3/8″ piston and uses the “scalloped” Enginetics pads which are still available. I just looked and Russell Karting has a set “in stock”. That’s were I got mine back in 2008.
Jeremy, did you really mean “aluminum spindle” in your post? Or did you mean an MCP style aluminum hub and brake carrier? I assume you mean the latter like shown the picture below. Brian also has 1/4″ thick cast iron discs for these hubs as well. I intend to get a pair of those.