{"title":"1200 Series LS Short Blocks (No Cylinder Heads)","description":"\u003cp class=\"MsoNormal\"\u003e\u003cspan lang=\"EN\" style=\"font-size: 11.5pt; line-height: 115%; color: #1c1c1c; background: white; mso-highlight: white;\"\u003eThe BoostLine Performance 1200 Series Short Blocks represent your best way to make big power reliably within a budget. These short blocks utilize established OEM components from the LS architecture in combination with the right aftermarket components. The precision machine work is then carried out on cutting-edge CNC machines under the oversight of Tommy Keeter, the experienced owner of KPE Racing. All parts are detailed and assembly of these short blocks is carried out by the proficient crew at BoostLine Performance, powered by KPE.\u003c\/span\u003e\u003c\/p\u003e\n\u003c!----\u003e","products":[{"product_id":"1200-series-408-short-block","title":"408 LS Short Block - 1200 Series","description":"\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 10.0pt; line-height: 115%; font-family: 'Arial',sans-serif; mso-fareast-font-family: Arial; mso-ansi-language: EN; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;\" lang=\"EN\"\u003eOur 1200 Series 408 Short block has all the ingredients to pack the punch your looking for.\u003cspan style=\"mso-spacerun: yes;\"\u003e  \u003c\/span\u003eThe popular, 408 LS combo is a proven performer and is a solid foundation for your ride\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 10.0pt; line-height: 115%;\" lang=\"EN\"\u003ePlan to clear 600HP NA with the right cam and intake selection!\u003cspan style=\"mso-spacerun: yes;\"\u003e  \u003c\/span\u003eThis package is still dependable at the 1200HP mark if you want to put a little extra squeeze on it with your choice of power adder.\u003cspan style=\"mso-spacerun: yes;\"\u003e  \u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cstrong\u003e\u003cspan style=\"font-size: 10.0pt; line-height: 115%;\" lang=\"EN\"\u003eBuild Specs:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eGM Iron 6.0 Block\u003c\/li\u003e\n\u003cli\u003eForged 4\" Stroke Crank\u003c\/li\u003e\n\u003cli\u003eARP Main Studs\u003c\/li\u003e\n\u003cli\u003eForged H-Beam Rods with ARP bolts\u003c\/li\u003e\n\u003cli\u003e2618 Forged Pistons - Your choice of Flat Top or Dish\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eCloyes timing chain dampener, also added to all gen 3 builds\u003c\/li\u003e\n\u003cli\u003eClevite Main \u0026amp; Rod Bearings\u003c\/li\u003e\n\u003cli\u003eDurabond Cam Bearings\u003c\/li\u003e\n\u003cli\u003eNew block plug kit and barbell\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!----\u003e","brand":"My Store","offers":[{"title":"Default Title","offer_id":48890939113767,"sku":"BL4081200SB","price":6450.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0878\/0664\/0423\/files\/SSSLSSB.png?v=1766001661"},{"product_id":"1200-series-383-short-block","title":"383 LS Short Block - 1200 Series","description":"\u003cp class=\"MsoNormal\"\u003e\u003cspan lang=\"EN\" style=\"font-size: 10.0pt; line-height: 115%;\"\u003eOur 1200 Series 383 long block is not to be confused with the ole, ever popular 383’s of the past.\u003cspan style=\"mso-spacerun: yes;\"\u003e  \u003c\/span\u003eThis modernized 383 will blow the minds of some old timers that like to reminisce about the old days and their mouse motor strokers.\u003cspan style=\"mso-spacerun: yes;\"\u003e  \u003c\/span\u003eWe take a standard 5.3 truck motor and transform it into a very capable package.\u003cspan style=\"mso-spacerun: yes;\"\u003e  \u003c\/span\u003eWhether you want the fastest Silverado in your neck of the woods or looking to power that muscle car undertaking an LS swap, this is a package worth considering.\u003cspan style=\"mso-spacerun: yes;\"\u003e  \u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cspan style=\"font-size: 10.0pt; line-height: 115%;\" lang=\"EN\"\u003ePlan to clear 600HP NA with the right cam and intake selection!\u003cspan style=\"mso-spacerun: yes;\"\u003e  \u003c\/span\u003eThis package is still dependable at the 1200HP mark if you want to put a little extra squeeze on it with your choice of power adder.\u003cspan style=\"mso-spacerun: yes;\"\u003e  \u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cstrong\u003e\u003cspan style=\"font-size: 10.0pt; line-height: 115%;\" lang=\"EN\"\u003eBuild Specs:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eGM Iron 5.3 Block\u003c\/li\u003e\n\u003cli\u003eForged 4\" Stroke Crank\u003c\/li\u003e\n\u003cli\u003eARP Main Studs\u003c\/li\u003e\n\u003cli\u003eForged H-Beam Rods with ARP bolts\u003c\/li\u003e\n\u003cli\u003e2618 Forged Pistons - Your choice of Flat Top or Dish\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eTotal Seal AP Steel, Gas Ported, Ring Set\u003c\/li\u003e\n\u003cli\u003eCloyes timing chain dampener, also added to all gen3 builds\u003c\/li\u003e\n\u003cli\u003eClevite Main \u0026amp; Rod Bearings\u003c\/li\u003e\n\u003cli\u003eDurabond Cam Bearings\u003c\/li\u003e\n\u003cli\u003eNew block plug kit and barbell\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!----\u003e","brand":"My Store","offers":[{"title":"Default Title","offer_id":48890980368679,"sku":"BL3831200SB","price":6125.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0878\/0664\/0423\/files\/SSSLSSB.png?v=1766001661"},{"product_id":"1200-series-388-sleeved-short-block","title":"388 Sleeved Aluminum LS Short Block -1200 Series","description":"\u003cp class=\"MsoNormal\"\u003e\u003cspan lang=\"EN\" style=\"font-size: 10.0pt; line-height: 115%; font-family: 'Arial',sans-serif; mso-fareast-font-family: Arial; mso-ansi-language: EN; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;\"\u003eOur Street-Strip Series 388 short block has all the ingredients to pack the punch you're after.\u003cspan style=\"mso-spacerun: yes;\"\u003e  \u003c\/span\u003eThe aluminum block 388 Darton Sleeved LS combo is a proven performer and is quickly becoming our most popular short block combination.  The 388 is a big bore (4.125\") with a short stroke (3.622\") making it a high rpm screamer and still allowing you to run a cylinder head that requires larger bore sizes, like the LS7 Style cylinder heads.  This combo has become the go to for power adder guys, no matter if it's boost or nitrous!\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cstrong\u003e\u003cspan lang=\"EN\" style=\"font-size: 10.0pt; line-height: 115%;\"\u003eBuild Specs:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan lang=\"EN\" style=\"font-size: 10.0pt; line-height: 115%;\"\u003eSeasoned GM Aluminum 5.3L Gen 4 Block with Darton Sleeves\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan lang=\"EN\" style=\"font-size: 10.0pt; line-height: 115%;\"\u003eBlocks are CNC Decked, CNC Bored and CNC Torque Plate Honed\u003c\/span\u003e\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\u003cspan lang=\"EN\"\u003e1600hp Extreme RPM CCW Crankshaft with welded reluctor wheel\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e1600hp Rated Heavy Duty Connecting Rods\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e2618 Forged Pistons (Dependent on Availability) Your choice of Flat Top or Dish\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cspan lang=\"EN\" style=\"font-size: 10.0pt; line-height: 115%;\"\u003e\u003cspan\u003eARP Main Studs\u003c\/span\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"font-size: 10pt;\"\u003eACL Main \u0026amp; Rod Bearings\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan lang=\"EN\" style=\"font-size: 10.0pt; line-height: 115%;\"\u003eDurabond Cam Bearings\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan lang=\"EN\" style=\"font-size: 10.0pt; line-height: 115%;\"\u003eNew block plug kit and barbell\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!----\u003e","brand":"My Store","offers":[{"title":"Default Title","offer_id":50316079038759,"sku":"BL3881200SSB","price":8999.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0878\/0664\/0423\/files\/388-427.png?v=1765999945"},{"product_id":"427-sleeved-aluminum-ls-short-block-1200-series","title":"427 Sleeved Aluminum LS Short Block - 1200 Series","description":"\u003cdiv data-is-intersecting=\"true\" data-turn-id-container=\"42a5f1ea-724c-4aee-a3e3-eeeed1c01c99\" class=\"\"\u003e\n\u003csection data-turn=\"user\" data-scroll-anchor=\"false\" data-testid=\"conversation-turn-7\" data-turn-id-container=\"42a5f1ea-724c-4aee-a3e3-eeeed1c01c99\" data-turn-id=\"42a5f1ea-724c-4aee-a3e3-eeeed1c01c99\" dir=\"auto\" class=\"text-token-text-primary w-full focus:outline-none has-data-writing-block:pointer-events-none [\u0026amp;:has([data-writing-block])\u0026gt;*]:pointer-events-auto R6Vx5W_threadScrollVars scroll-mb-[calc(var(--scroll-root-safe-area-inset-bottom,0px)+var(--thread-response-height))] scroll-mt-(--header-height)\"\u003e\n\u003cdiv class=\"text-base my-auto mx-auto pt-12 [--thread-content-margin:var(--thread-content-margin-xs,calc(var(--spacing)*4))] @w-sm\/main:[--thread-content-margin:var(--thread-content-margin-sm,calc(var(--spacing)*6))] @w-lg\/main:[--thread-content-margin:var(--thread-content-margin-lg,calc(var(--spacing)*16))] px-(--thread-content-margin)\"\u003e\n\u003cdiv class=\"[--thread-content-max-width:40rem] @w-lg\/main:[--thread-content-max-width:48rem] mx-auto max-w-(--thread-content-max-width) flex-1 group\/turn-messages focus-visible:outline-hidden relative flex w-full min-w-0 flex-col\"\u003e\n\u003cdiv class=\"flex max-w-full flex-col gap-4 grow\"\u003e\n\u003cdiv class=\"min-h-8 text-message relative flex w-full flex-col items-end gap-2 text-start break-words whitespace-normal outline-none keyboard-focused:focus-ring [.text-message+\u0026amp;]:mt-1\" dir=\"auto\" data-message-id=\"42a5f1ea-724c-4aee-a3e3-eeeed1c01c99\" data-message-author-role=\"user\"\u003e\n\u003cdiv class=\"flex w-full flex-col gap-1 empty:hidden items-end rtl:items-start\"\u003e\n\u003cdiv class=\"user-message-bubble-color corner-superellipse\/0.98 relative min-w-0 overflow-hidden rounded-[22px] px-4 py-2.5 leading-6 max-w-(--user-chat-width,70%)\"\u003e\n\u003cdiv class=\"max-w-full min-w-0 [overflow-wrap:anywhere] whitespace-pre-wrap\"\u003eOur 1200 Series 427 short block has all the ingredients to pack the punch you're after. The aluminum block 427 Darton Sleeved LS combo is a proven performer and is quickly becoming our most popular short block combination. The 427 is a big bore (4.125\") with a stroker crank (4.000\") making it a torquey beast. The large bore size allows you to use higher flowing cylinder heads, like the LS7 Style cylinder heads. This combo has become the go to for power adder guys, no matter if it's boost or nitrous!\u003c\/div\u003e\n\u003cdiv class=\"max-w-full min-w-0 [overflow-wrap:anywhere] whitespace-pre-wrap\"\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003c\/div\u003e\n\u003cp class=\"MsoNormal\"\u003e\u003cstrong\u003e\u003cspan style=\"font-size: 10.0pt; line-height: 115%;\" lang=\"EN\"\u003eBuild Specs:\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli class=\"MsoNormal\" style=\"text-align: left;\"\u003e\u003cspan lang=\"EN\"\u003eSeasoned GM Aluminum 5.3L Gen 4 Block with Darton Sleeves\u003c\/span\u003e\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cspan lang=\"EN\"\u003e\u003c\/span\u003e\u003cspan lang=\"EN\"\u003eBlocks are CNC Decked, CNC Bored and CNC Torque Plate Honed\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli class=\"MsoNormal\"\u003e\n\u003cspan lang=\"EN\"\u003e\u003c\/span\u003e\u003cspan lang=\"EN\"\u003e1600hp Extreme RPM CCW Crankshaft with welded reluctor wheel\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e1600hp Rated Heavy Duty Connecting Rods\u003c\/li\u003e\n\u003cli\u003e2618 Forged Pistons (Dependent on Availability) Your choice of Flat Top or Dish\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cspan lang=\"EN\"\u003e\u003cspan\u003eARP Main Studs\u003c\/span\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eACL Main \u0026amp; Rod Bearings\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan lang=\"EN\"\u003eDurabond Cam Bearings\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan lang=\"EN\"\u003eNew block plug kit and barbell\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!----\u003e","brand":"My Store","offers":[{"title":"Default Title","offer_id":52048127426855,"sku":"BL4271200SBA","price":9599.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0878\/0664\/0423\/files\/388-427.png?v=1765999945"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0878\/0664\/0423\/collections\/LongblockCat_33aca2b1-0afe-4ca3-9b60-40249cdf6ccc.png?v=1791232237","url":"https:\/\/www.boostlineperformance.com\/collections\/1000-series-ls-short-blocks-no-cylinder-heads-copy.oembed","provider":"Boostline Performance","version":"1.0","type":"link"}