Build Your Own Gen III HEMI CGI Engine Block – Custom Configuration

Configure your block to your exact combination. This is the custom-build path — every deck height, lifter type, timing drive, cam tunnel, bore, and finish we offer, in every valid combination. If your build does not match one of our four ready-made configurations, this is where you spec it.

Looking for a simpler starting point? Four proven configurations are set up as their own pages, each one build, one price, nothing to configure: ACE STREET ($4,200 · drop-in, factory VCT) · ACE BOOST ($5,000 · tall deck for forced induction) · ACE DRAG PAK ($5,600 · drag and bracket race) · ACE MAMMOTH ($6,700 · 4.300" max bore, honed, naturally aspirated only).

How pricing works

Every block starts at $4,200. From there, only three things change the price — bore size does not.

Bore sizes

4.300" is naturally aspirated only. It is the largest bore we make, and at that diameter the cylinder walls are specified for NA use — not for forced induction. If your build is boosted, choose 4.260" or smaller, or call us and we will spec a boost-safe big-bore combination.

Price range across every combination: $4,200 to $6,800.

Rough or honed?

Rough ships .003" undersize for your machine shop to finish-hone to final bore before ring fit — the standard approach, and it lets your shop match the hone to your ring package. Plateau-honed is finished to final size here on the same CMM-verified equipment that cut the block, ready for ring fit with no further machine work. Honed costs $300 more and usually saves more than that in shop time.

Before you configure — two things that decide the rest

Deck height. Two heights are offered: standard 9.285" and tall 10.75". A tall deck needs tall-deck-length intake, pushrods, and matching front-drive components. Standard 9.285" parts will not carry over.

VCT or non-VCT. Non-VCT configurations run a fixed-timing front drive and are not compatible with factory variable cam timing — they need a non-VCT cam. The 937 roller-guided splay lifters also need a cam ground to match.

These two choices drive your whole supporting parts list. If either one is not settled, call before you order.

ACE CGI engineering — on every block

• Compacted graphite iron, 450 MPa minimum tensile strength (GJV-450)
• Big bore capability to 4.310" (109.5 mm), with 4 mm minimum cylinder wall thickness at max bore
• Two deck heights: standard 9.285" and tall 10.75"
• 19 mm (0.75") minimum deck thickness on the 9.285" deck; the 10.75" deck carries an additional 0.25" for a full 1" (25.4 mm) minimum deck
• 6-bolt 4140 billet steel main caps on all five mains
• Race cam and splayed lifter options for high RPM and ACE INC high-flow heads: up to 82 mm cam journals and 1.2" roller lifters in guided, bushed bores
• Stroker clearance for 5.100" stroke with 2.200" rod journals
• M14 head stud threads in the deck for stronger thread engagement in the CGI. Standard studs neck to an M12 fine nut end; an optional M14 both-ends stud delivers up to 36% more clamp load than an M12 fastener
• 9.5" head studs for roughly 50% more stretch compliance. Clamp load stays stable through a knock event, and cylinder wall stress concentration moves to the bottom of the bore where sealing demand is lowest
• Revised oiling: true priority main oil gallery, dedicated lifter secondary circuit, and a straight filter-to-MOG feed with no 90° turns causing pressure drop or cavitation
• Dry sump oil feed provision at the front face of block or at the oil filter feed
• Fully water jacketed. Race block strength, street driveable
• Cast-in -8 ORB oil drain-back ports at the pan rail by cylinders 1 and 2
• 100% stock mount compatibility, including TRX engine mounts and SUV front differential mounts
• Serialized castings; every block ships with its CMM report and full QC documentation covering both casting and machining
• 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 which combination is right? Talk to an ACE engineer before you order: eric@aceinc.shop · (615) 924-2737. Bring your cam card and your power target — ten minutes on the phone beats a block that does not match your parts.