{"product_id":"ace-mammoth-gen-iii-hemi-cgi-block","title":"ACE MAMMOTH – Gen III HEMI CGI Engine Block | 4.300\" Honed, Tall Deck, Naturally Aspirated","description":"\u003cp\u003e\u003cstrong\u003eMaximum cubic inches.\u003c\/strong\u003e ACE MAMMOTH is the big-bore block — 4.300\", the largest bore we make, plateau-honed at our shop and ready for ring fit, on a tall 10.75\" deck with 937 roller-guided splay lifter bushings and a non-VCT 60mm roller cam tunnel. It is the only block in the fixed lineup that arrives finish-honed, which takes a machine shop operation and its cost out of your build.\u003c\/p\u003e\n\n\u003cp style=\"border-left:4px solid #8b4dab;padding:10px 0 10px 16px;margin:18px 0;\"\u003e\u003cstrong\u003eNaturally aspirated only.\u003c\/strong\u003e At 4.300\" the cylinder walls are specified for naturally aspirated use. This block is not rated for forced induction — do not run a supercharger or turbo on it. Building boost? Use \u003ca href=\"\/products\/ace-boost-gen-iii-hemi-cgi-block\"\u003eACE BOOST\u003c\/a\u003e, or call us and we will spec a boost-safe big-bore combination for you.\u003c\/p\u003e\n\n\u003ch3\u003eThis build\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDeck height \u0026amp; lifters:\u003c\/strong\u003e Tall 10.75\" deck, 937 roller-guided splay lifter bushings\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTiming drive \u0026amp; cam:\u003c\/strong\u003e Non-VCT, 60mm roller cam tunnel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBore \u0026amp; finish:\u003c\/strong\u003e 4.300\", plateau-honed — naturally aspirated only\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrice:\u003c\/strong\u003e $6,700 — direct from the manufacturer\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFitment\u003c\/h3\u003e\n\u003cp\u003eMax-displacement naturally aspirated Gen III HEMI builds — pro street, show, and NA race engines. Tall 10.75\" deck, 937 splay roller-guided lifters for high-RPM valvetrain and ACE INC high-flow heads, and a 60mm roller cam tunnel for big lift. If your combination is naturally aspirated and you want every cubic inch available, this is the block.\u003c\/p\u003e\n\n\u003ch3\u003eMachine work required — none\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003ePlateau-honed to final size at the factory.\u003c\/strong\u003e Ready for ring fit, no finish-honing needed. Against the rough-bore options that is a real saving in both machine shop time and cost, and at 4.300\" it matters more than usual — this is the largest bore we cut, and it is finished on the same CMM-verified equipment that machined the block.\u003c\/p\u003e\n\n\u003ch3\u003eSupporting parts — read this before ordering\u003c\/h3\u003e\n\u003cp\u003eThree things about this block drive your parts list:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNaturally aspirated only.\u003c\/strong\u003e No supercharger, no turbo. See the note above.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTall deck.\u003c\/strong\u003e Requires tall-deck-length intake, pushrods, and matching front-drive components. Standard 9.285\"-deck parts will not carry over.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNon-VCT.\u003c\/strong\u003e Runs a fixed-timing front drive, not compatible with factory variable cam timing. Needs a non-VCT cam ground to suit the 937 roller-guided splay lifters.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eCall before you order and we will check the whole combination with you.\u003c\/p\u003e\n\n\u003ch3\u003eACE CGI engineering — on every block\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eCompacted graphite iron, 450 MPa minimum tensile strength (GJV-450)\u003c\/li\u003e\n\u003cli\u003eBig bore capability with 4 mm minimum cylinder wall thickness at maximum bore\u003c\/li\u003e\n\u003cli\u003e6-bolt 4140 billet steel main caps on all five mains\u003c\/li\u003e\n\u003cli\u003eM14 head stud threads in the deck; 9.5\" studs for roughly 50% more stretch compliance, so clamp load stays stable through a knock event\u003c\/li\u003e\n\u003cli\u003eTrue priority main oil gallery, dedicated lifter secondary circuit, and a straight filter-to-MOG feed with no 90° turns\u003c\/li\u003e\n\u003cli\u003eDry sump feed provision; cast-in -8 ORB oil drain-back ports at the pan rail by cylinders 1 and 2\u003c\/li\u003e\n\u003cli\u003eStroker clearance for 5.100\" stroke with 2.200\" rod journals\u003c\/li\u003e\n\u003cli\u003eFully water jacketed — race block strength, street driveable\u003c\/li\u003e\n\u003cli\u003eSerialized casting, shipped with its CMM report and full casting and machining QC documentation\u003c\/li\u003e\n\u003cli\u003eCast and machined in-house at our Michigan foundry and CNC cell\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eOrdering\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003ePRE-ORDER\u003c\/strong\u003e — reserve your block now. Orders are fulfilled in the sequence received, and we confirm your production slot by email once your order is placed.\u003c\/p\u003e\n\u003cp\u003eFull payment at checkout. Direct from the manufacturer — same price for everyone, no dealer markup, no middlemen. Free shipping within the USA.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003ePlanning a big-bore build?\u003c\/strong\u003e Talk to an ACE engineer first: \u003ca href=\"mailto:eric@aceinc.shop\"\u003eeric@aceinc.shop\u003c\/a\u003e · \u003ca href=\"tel:+16159242737\"\u003e(615) 924-2737\u003c\/a\u003e. We will confirm the right bore and deck for your power target before you commit — especially worth a call if there is any chance boost is in the plan.\u003c\/p\u003e\n\n\u003ch3\u003eNeed a different bore, deck, or cam setup?\u003c\/h3\u003e\n\u003cp\u003eACE MAMMOTH is one fixed configuration. Every other combination — standard deck, stock lifters, VCT front drives, smaller bores rated for boost, rough finishes, and the 82mm Pro-Stock cam tunnel — is available on our \u003ca href=\"\/products\/gen-iii-hemi-engine-block-cgi\"\u003eBuild Your Own Gen III HEMI CGI Block\u003c\/a\u003e page.\u003c\/p\u003e","brand":"ACE INC","offers":[{"title":"Default Title","offer_id":48333911163138,"sku":"ACE-BLK-MAMMOTH","price":6700.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0797\/8693\/4530\/files\/gen-iii-hemi-engine-block-cgi-purple_6177781d-b537-407e-be46-8f375b801684.jpg?v=1786706118","url":"https:\/\/aceinc.shop\/products\/ace-mammoth-gen-iii-hemi-cgi-block","provider":"ACE INC ","version":"1.0","type":"link"}