I'm using the Moroso tank (#63651). It's mounted out from the bulkhead with 4" standoffs. Be sure to buy the model with the billet fill neck if you choose this type. The standoffs were made from a solid 3/4" aluminum rod (1 foot in length) cut into three 4" pieces. I then drilled and tapped each end of the three rods with a 3/8 tap. http://www.summitracing.com/dom/parts/mor-63651/overview/
I have the custom expansion tank. In the build manual, the diagram shows an additional overflow tank. Do we have one from RCR and is there supposed to be one used?
The overflow tank is needed to catch the coolant that bypasses the cap. It's not provided with the kit. TIP: don't mount it in front of the rear wheels.