ACE BOOST – Gen III HEMI CGI Engine Block | 4.210" Tall Deck, Factory VCT

Tall deck strength, factory timing control. ACE BOOST is the block for turbo and supercharged Gen III HEMI builds that still want to run factory variable cam timing. The 10.75" tall deck adds cylinder wall and deck material where boost loads it hardest, and the 4.210" bore opens up displacement without giving up the stock-style timing strategy you already tune around.

This build

• Deck height & lifters: Tall 10.75" deck, stock 74° lifters
• Timing drive & cam: VCT (variable cam timing) with stock cam
• Bore & finish: 4.210", rough
• Price: $5,000 — direct from the manufacturer

Fitment

Built for forced induction on the Gen III HEMI. The 4.210" performance bore and tall 10.75" deck give you added cylinder strength under boost, with factory VCT retained so you keep stock-style timing control.

Machine work required

Rough bore. This block ships .003" undersize at 4.210". Your machine shop finish-hones it to final bore before ring fit, matched to your ring package.

Supporting parts — read this before ordering

This is a tall-deck build. It requires tall-deck-length intake, pushrods, and matching timing and front-drive components. Standard 9.285"-deck parts will not fit. If you are moving to a tall deck for the first time, call us and we will walk your boost combination through the supporting parts list so nothing arrives that does not fit.

ACE CGI engineering — on every block

• Compacted graphite iron, 450 MPa minimum tensile strength (GJV-450)
• 6-bolt 4140 billet steel main caps on all five mains
• M14 head stud threads in the deck; 9.5" studs for roughly 50% more stretch compliance, so clamp load stays stable through a knock event — which matters most on a boosted engine
• True priority main oil gallery, dedicated lifter secondary circuit, and a straight filter-to-MOG feed with no 90° turns
• Dry sump feed provision; cast-in -8 ORB oil drain-back ports at the pan rail by cylinders 1 and 2
• Fully water jacketed — race block strength, street driveable
• 100% stock mount compatibility, including TRX engine mounts and SUV front differential mounts
• Serialized casting, shipped with its CMM report and full casting and machining QC documentation
• Cast and machined in-house at our Michigan foundry and CNC cell

Ordering

PRE-ORDER — reserve your block now. Orders are fulfilled in the sequence received, and we confirm your production slot by email once your order is placed.

Full payment at checkout. Direct from the manufacturer — same price for everyone, no dealer markup, no middlemen. Free shipping within the USA.

Not sure it fits your build? Talk to an ACE engineer before you order: eric@aceinc.shop · (615) 924-2737. Confirm your boost combination with us and we will make sure the deck height and supporting parts line up.

Need a different bore, deck, or cam setup?

ACE BOOST is one fixed configuration. Every other combination — standard deck, splay roller lifters, non-VCT front drives, other bores, factory-honed finishes — is available on our Build Your Own Gen III HEMI CGI Block page.