Sealed GM 604 crate engine rules leave very little room to gain airflow through the carburetor itself, which is exactly where a well-designed spacer makes its difference. HVH's Super Sucker spacer is sized specifically for the 604's 4150 carb base, adding plenum volume without touching anything the rulebook restricts.

HVH SS4150-604AL Super Sucker Carburetor Spacer Features:

• Sized for GM 604 crate engines.
• 4150 series, 4-hole design.
• 0.650 in. thickness.
• Polished aluminum construction.
• Sold individually.