Proflow Carburettor Spacer, Aluminium, 2 in. Thick, Tapered Combo, 4500 Square Bore - PFESSLW45002ALPart Number: PFESSLW45002AL These billet aluminium tapered spacers can increase flow rates through the carburettor by as much as 100 CFM. They will increase torque, horsepower and acceleration throughout the entire RPM range, offering smooth power delivery. These are available in 4150 and 4500 versions in either a silver or black anodised finish. This provides high performance consumers with the ability to tune their engines for maximum performance on