The following chart illustrates the differences on some of the Bow Tie 18° competition manifolds. These manifolds all fit 18° Chevrolet small-block cylinder heads and have single-plane design with air gaps underneath the manifold's runners to insulate the intake charge from engine heat. The manifold flanges are 0.59" thick to promote a good gasket seal. These manifolds have an auxiliary water line boss at the rear of the casting to improve water flow. Both GM#24502481 and GM#24502487 have squared carburetor flange openings to match the spacers specified by NASCAR.

10185053 - 18° Aluminum Intake Manifold     Price  $259.16

This aluminum intake manifold is designed exclusively for competition. It uses the new Chevy 18° cylinder head (GM#10134363). This utilizes a high port runner and four-barrel single plane design, and has the same benefits as the Bow Tie intake manifold GM#10051103. The overall height of this manifold is 6.75". Drilled for Holley bolt pattern.

24502481 - 18° Aluminum Intake Manifold     Price  $259.16

Fits 18° cylinder head GM#10134363 and GM#24502482. This aluminum intake manifold was developed for NASCAR's shorter tracks and has smaller runners and less plenum volume than the GM#10185053 to enhance mid-range torque. This manifold has worked well on trans-am engines.

24502487 - 18° Aluminum Intake Manifold    Price  $262.53

This aluminum intake manifold is a revised version of the original Bow Tie intake. Material was removed from the outer walls of the four runners for an improved "line of sight" path to the cylinder head's intake port. Aluminum was also added to the walls to provide more raw material for porting. This updated manifold is designed to enhance mid-to-high RPM power.

24502579 - 18° Light Weight Race Manifold     Price  $293.76

This light weight aluminum racing manifold is 10 pounds lighter than the original short track casting GM#24502481. This new light weight design reduces weight where the impact on handling is greatest, high and forward in the chassis. This manifold's port volumes and runner shapes duplicate a professionally prepared manifold and requires only minimal preparation for top performance. This manifold is recommended for 310cid road racing and 358cid short track engines.

Technical Note:  See GM#24502481 for more details.

 

24502653 - 18° Aluminum Spider Manifold     Price  $130.85

This two-piece "dry" aluminum manifold design consists of the "runners" and "plenum" only. The Spider along with Valley Plate assembly GM#24502654 (below) is designed for use with the Chevy 18° cylinder head with date code of June 1996 or later only. This design is based on the original 18° Bow Tie manifold GM#10185053 and is currently used in competition.

 

24502654 - Aluminum Valley Plate Assembly     Price  $157.01

This "universal" aluminum valley plate is designed for use with Chevy 18° cylinder heads. It can be used in conjunction with "dedicated" two-piece manifold spiders, existing one-piece intake manifolds which have been properly machined for use as a "dry" manifold, or "fabricated" manifold designs. The valley plate assembly consists of the following pieces: the valley plate GM#24502652, the inspection cover GM#24502651, "O-ring" material, and eight retaining bolts. The valley plate has cast-in integral passages to equalize coolant flow from the front and the rear of the cylinder heads. Fits heads dated June 1996 or later.

24502587 -  SB2 Engine Valley Cover     Price  $236.36

This aluminum valley cover is required when the upper manifold GM#24502588 is used on the new V8 SB2 design cylinder heads. This valley cover handles the water crossover, water outlet, and distributor mounting.

Technical Note:  The width of the lifter valley cover is designed for a block with a 9.000" deck height and .060" thick valley cover gaskets.

12370840 - SB2.2 Engine Valley Cover    Price  $203.96

This aluminum engine valley cover is used with manifold runners GM#12370854 on SB2.2 cylinder heads for NASCAR racing.

24502588 -  SB2 "Upper" Intake Manifold     Price  $210.20

This aluminum upper manifold for the "SB2 Head Only" is a spider design for maximum fuel distribution. This manifold is a plenum and runners only with the Valley Cover GM#24502587 handling the water cross-over. Damns on the floor of the manifold plenum are designed to equalize fuel distribution between the middle and end cylinders.

Technical Note:  A one-inch tall carburetor plate is recommended if hood clearance is sufficient.

12370854 - SB2.2 "Upper" Intake Manifold    Price  $215.62

This aluminum upper manifold is used with Valley cover GM#12370840 on SB2.2 cylinder heads for NASCAR racing. This is the new design upper spider manifold similar to GM#24505988 which is used on the SB2 engine.