BDS CARBS By ATM’s Gas XRSB Series are our most versatile "street/strip" race carburetors for Blowers Specific, with a 4150-style flange and "with vacuum ports". They are the perfect blend of a precision die cast aluminum ATM™ carb body with ATM 2-circuit, 4-emulsion billet metering blocks. Fuel is managed by ATM™ all aluminum dual inlet, dual sight-window fuel bowls and the billet aluminum throttle-bodies have vacuum tubes for vacuum advance and PVC hookups. They are available in 5 sizes from 650cfm to 1050cfm (4150 flange) applications.