I use Manhatten brand. I pick mine up just a mile away at Townsends performace....I beleive Summit is the manhatten brand as well
I would check local performance shop's in your town, it will save you a few buck's in shipping and give's you a reason to ride your MB.

Manhattan Oil & Liquid Horsepower
Townsend's Performance and Speed Automotive Racing Products for Cars and Trucks
Speedway Motors - Street Rod Parts, Race Parts, Ford Flathead Parts, Sprint and Midget Racing Parts, Pedal Car Parts
Day Motor Sports ~ Circle Track Racing Parts

The kid's love it