Abstract: An intake manifold for an internal combustion engine that distributes a fuel-air mixture to an engine. The manifold includes a box-shaped chamber defined by at least four sidewalls. The chamber is mounted atop multiple intake runners, and opens to an intake plenum to which multiple runners are joined. The box-shaped chamber can include a mounting flange to which a substantially planar cover plate can be mounted to close the top of the box-shaped chamber. The cover plate can define at least one hole to accommodate a carburetor, throttle body or other fuel-air mixture delivery device.

Abstract: An adjustable pushrod guide plate assembly including a first plate and a second plate. Each plate defines an adjustment slot. The plates are in an at least partially overlapping configuration, the slots are optionally aligned, and a shaft is disposed at least partially through the slots to join the plates. The shaft can be a fastener adapted to be manipulated to secure the plates in a variety of fixed configurations.