Holley Chrome Vacuum Secondary Diaphragm Housing and Cover 34-503 Chassis Helps improve engine efficiency with

Helps improve engine efficiency with better air flow

Fully adjustable up to 3” (76

2-7/8” overall depth

Turn-off temperature is preset at 10ºF below turn-on temperature

14” Flat Laminated 9 Bolt

Holley Chrome Vacuum Secondary Diaphragm Housing and Cover 34-503 Chassis Helps improve engine efficiency withGenuine Holley Vacuum Secondary Diaphragm Housings and Covers are designed to replace your existing cover without any modifications. They are made of die cast aluminium and are chrome plated for durability. Sold individually, discontinued by Holley making these rare and hard to find. Holley Part No. 34 503 If carburetor is equipped with a black plastic cover then you must also purchase a special choke cable clamp kit, Holley Part No. 45 456, if you