{"product":{"id":11350217982294,"title":"Kooks 1-7\/8 x 3-1\/2-inch Weld-Up Header Kit | WK2450","body_html":"\u003ch2\u003eCustom headers with the collector size you need\u003c\/h2\u003e\u003cp\u003eKeep 1-7\/8-inch primary tubing and choose a 3-1\/2-inch collector outlet with Kooks WK2450. The 304 stainless weld-up kit lets your fabricator make the header shape around the engine and available space in your project.\u003c\/p\u003e\u003cp\u003eSKU: WK2450\u003c\/p\u003e\u003ch2\u003eTubes and collectors included\u003c\/h2\u003e\u003cp\u003eTwelve JB-188-25-16-304 J-bends and two 9906S collectors are supplied. Compared with the 3-inch-outlet kit, the main change is the collector outlet, so choose around the intended downstream exhaust. The two 9906S collectors have a four-into-one slip-on design with a scavenging spike, 1-7\/8-inch inside-diameter inlets and 3-1\/2-inch outside-diameter outlets. The inlets slip over the matching primary tubes, ready for your fabricator to position them. The twelve JB-188-25-16-304 J-bends are 16-gauge, mandrel-bent 180-degree tubing with a 2.50-inch centreline radius.\u003c\/p\u003e\u003ch2\u003eComplete the kit with your head flanges\u003c\/h2\u003e\u003cp\u003eTwo header flanges are purchased separately. The exact cylinder-head port and bolt pattern should determine that choice, with final pipe routing established before welding.\u003c\/p\u003e\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\u003cdiv class=\"table-scroll\"\u003e\u003ctable class=\"technical-specifications\"\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth scope=\"col\"\u003eSpecification\u003c\/th\u003e\n\u003cth scope=\"col\"\u003eDetails\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eSKU\u003c\/td\u003e\n\u003ctd\u003eWK2450\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eWeld-up custom header fabrication\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary tube diameter\u003c\/td\u003e\n\u003ctd\u003e1-7\/8-inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCollector outlet diameter\u003c\/td\u003e\n\u003ctd\u003e3-1\/2-inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIncluded bends\u003c\/td\u003e\n\u003ctd\u003eTwelve JB-188-25-16-304 J-bends\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIncluded collectors\u003c\/td\u003e\n\u003ctd\u003eTwo 9906S collectors\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHeader flanges\u003c\/td\u003e\n\u003ctd\u003eTwo flanges required; purchased separately\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIncluded collector design\u003c\/td\u003e\n\u003ctd\u003eTwo 9906S four-into-one slip-on collectors with scavenging spikes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCollector inlet \/ outlet\u003c\/td\u003e\n\u003ctd\u003e1-7\/8-inch inside-diameter inlet \/ 3-1\/2-inch outside-diameter outlet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eJ-bend construction\u003c\/td\u003e\n\u003ctd\u003eTwelve JB-188-25-16-304; 16-gauge, mandrel-bent 180-degree tubing; 2.50-inch centreline radius\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003e304 stainless steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003c\/div\u003e\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\u003ch3\u003eWhat is the difference from WK2400?\u003c\/h3\u003e\u003cp\u003eWK2450 has 3-1\/2-inch-outlet collectors; WK2400 has 3-inch-outlet collectors. Both use 1-7\/8-inch J-bends.\u003c\/p\u003e\u003ch3\u003eHow many flanges do I need?\u003c\/h3\u003e\u003cp\u003eTwo cylinder-head flanges, purchased separately for the engine in your project.\u003c\/p\u003e\u003ch2\u003eOrdering and delivery\u003c\/h2\u003e\u003cp\u003eEstimated lead time is 4-6 weeks. Delivery may be faster depending on stock levels. Shipping is charged separately.\u003c\/p\u003e","vendor":"Kooks","product_type":"Exhaust Fabrication Components","created_at":"2026-10-08T10:41:43+01:00","handle":"kooks-wk2450","updated_at":"2026-10-11T10:15:03+01:00","published_at":"2026-10-09T13:36:54+01:00","template_suffix":null,"published_scope":"global","tags":"brand:kooks, cat:exhausts, class:equipment-service-non-vehicle, dept:performance-parts, type:exhaust-fabrication-component","variants":[{"id":55646909890902,"product_id":11350217982294,"title":"Default Title","price":"901.91","sku":"WK2450","position":1,"compare_at_price":"","fulfillment_service":"manual","inventory_management":null,"option1":"Default Title","option2":null,"option3":null,"created_at":"2026-10-08T10:41:44+01:00","updated_at":"2026-10-11T10:15:03+01:00","taxable":true,"barcode":"842422180171","grams":20412,"image_id":null,"weight":20.412,"weight_unit":"kg","requires_shipping":true,"quantity_rule":{"min":1,"max":null,"increment":1},"price_currency":"GBP","compare_at_price_currency":"","quantity_price_breaks":[]}],"options":[{"id":14512401940822,"product_id":11350217982294,"name":"Title","position":1,"values":["Default Title"]}],"images":[{"id":86449302733142,"product_id":11350217982294,"position":1,"created_at":"2026-10-08T10:41:44+01:00","updated_at":"2026-10-08T10:41:46+01:00","alt":"Kooks 1-7\/8\" x 3-1\/2\" 304 Stainless Steel Weld Up Custom Header Kit","width":1103,"height":762,"src":"https:\/\/cdn.shopify.com\/s\/files\/1\/0952\/1849\/9926\/files\/d62fa362c3739229c3cd1da3ff199008_2be7a4c5-5c3a-4d77-aeaf-13a39b41fbc1.jpg?v=1791452506","variant_ids":[]}],"image":{"id":86449302733142,"product_id":11350217982294,"position":1,"created_at":"2026-10-08T10:41:44+01:00","updated_at":"2026-10-08T10:41:46+01:00","alt":"Kooks 1-7\/8\" x 3-1\/2\" 304 Stainless Steel Weld Up Custom Header Kit","width":1103,"height":762,"src":"https:\/\/cdn.shopify.com\/s\/files\/1\/0952\/1849\/9926\/files\/d62fa362c3739229c3cd1da3ff199008_2be7a4c5-5c3a-4d77-aeaf-13a39b41fbc1.jpg?v=1791452506","variant_ids":[]}}}