Ultra XP Aluminum Fuel Bowl Kit Tumble Polished Ultra XP Aluminum Fuel Bowl Kit Fits Models 4150, 4160 & 4500 (will Require a .250 Longer Fuel Line) Tumble Polished Finish HolleyUltra Xp Aluminum Fuel Bowl Kit. Fits models 4150, 4160 & 4500. (Will require a . 250 inch longer fuel line). Tumble Polished finish Features and Benefits: use of o ring fittings Bowls use standard traditional floats, float hangers, screws, accelerator diaphragms, etc Features Clear Pyrex sight windows on both sides of bowl Fuel trough designed in floor of bowl to route fuel directly to jets & assists to keep jets covered Internal baffling cast into