Hygrade 661A

Hygrade 661A is a Holley four-barrel carburetor repair kit with broad coverage for classic Ford, Mercury, and American Motors vehicles and selected Ford marine engines.

Application / fitment

This kit covers specific Holley 4BBL carburetor numbers used from the late 1950s through the early 1970s. The Standard/Hygrade catalog includes selected Ford and Mercury 4.3 / 260, 4.7 / 289, 5.0 / 302, 5.4 / 332, 5.8 / 351, 5.8 / 352, 6.4 / 390, 6.7 / 406, 6.7 / 410, 7.0 / 427, 7.0 / 428, 7.0 / 429, and 7.0 / 430 engines. Selected American Motors 4.1 / 250 and 5.4 / 327 applications are also listed.

• carburetor make: Holley
• carburetor type: 4BBL / four-barrel
• selected numbers: 5752303, R1847-1, R1848-1, R1850, R2112, R2142, R2143, R2652, R3113, R3115, R3489-R3492, R4005, R4006, R4452, R4548, R4550, R6291, R6520, R6590, R6591, R7053
• confirmed Ford marine numbers: R6407, R6408, R4473, R6151, R6152
• Ford marine engines: 5.0 / 302, 5.8 / 351C, and 5.8 / 351W

The complete Holley carburetor number is the primary identification point. Read it from the choke tower or main body and compare it with the catalog list, because visually similar carburetors can use different passages, floats, and calibration components.

Technical information

• part type: carburetor repair kit
• carburetor: Holley 4BBL
• automotive coverage: selected Ford, Mercury, and American Motors
• marine coverage: selected Holley carburetors for Ford 302, 351C, and 351W engines
• service scope: rebuilding after disassembly, cleaning, and body inspection
• installation instructions: included
• sale unit: 1 repair kit