To ensure adequate hood clearance, check the height of your stock manifold and compare the "A" and "B" measurements against those of the Edelbrock manifold prior to purchase. The heights of all Edelbrock manifolds can be seen on the installation notes tab on product pages.
MSD Performance first produced the after-market distributor, made from a billet of 6061-T6 aluminum. These Pro-Billet Distributors can now be purchased for the majority of popular domestic V8s, as well as for a number of other popular engines. There are several different versions of after-market distributors on offer. Some things are the same throughout the distributor line, like the seal design and upper ball bearing to guide the QPQ-coated shaft and the pickup that is non-magnetic, but several lines are also designed to suit different specific applications....
Spacers come in different designs and materials. The most common types of spacers are so-called 4-Hole, divided wall, or open Spacers. They are available in aluminum, wood fiber laminate, plastic, or rubber gasket material. Which one you need depends on what you want to use it for. Spacers are used for various purposes. The 2 main reasons are to adjust the power band of your engine or to prevent heat problems; such as vapor lock.