DCI Pontiac 400 Stroked to 455 Crate Engine
DCI 400-455 is DCI’s most popular crate engine. Featuring a Pontiac 400 cubic inch block stroked to 455 cubic inches, this authentic Pontiac stroker is perfect for street and strip use. The 400-455 is pump gas friendly for the mild daily driver. Based on production block and heads, this combination provides plenty of power with quality bottom end components to allow for endless upgrades.
The DCI 400-455 is used as the foundation for most custom built DCI engines. Please see upgrades section for a list of possibilities.
- Engine Displacement: 455 ci
- Horsepower: 550
- Torque: 575 lb-ft
- Bore/Stroke: 4.155/4.21
- Block/Crank Combo: Pontiac 400 block, Eagle cast crankshaft
- Bore/Stroke Ratio: .98:1
- Rod/Stroke Ratio: 1.57:1
The DCI 400-455 is capable of mid-11 second quarter mile times (3.55 gears and 3,200 rpm stall converter recommended for 3,500 pound car).
| Feature | Detail |
|---|---|
| Block | Factory Pontiac 400 two-bolt main |
| Year | 1970-1974 |
| Preparation | Hot-tanked, magged for cracks, bored and honed with deck plates, deburred, new cam bearings, new brass freeze plugs, checked and cleaned for assembly |
| Deck Height | Stock, 10.225" |
| Crank | Eagle cast stroker crank 3" mains, 2.25" rod journals |
| Crank Preparation | Cleaned, inspected, checked for bearing clearances and journals out of round, micro-polished, and balanced |
| Balancer | Factory GM, two-piece cast-iron |
| Rods | Eagle 4340 H-beam, 6.625" |
| Rod Preparation | Cleaned, big and small ends checked and fitted if needed |
| Bearings | Speed Pro 3/4-groove mains, Clevite 77 rod, Clevite cam bearings |
| Bearing Preparation | Cleaned and inspected, checked for clearance |
| Pistons | Speed Pro Forged |
| Piston Preparation | Pin-fitted, deburred, weight-matched and cleaned |
| Piston to Deck Height | 0.010" |
| Piston Pins | Speed Pro, pressed or floating with double locks |
| Rings | Speed Pro file-fit |
| Ring Preparation | Fitted to each individual bore, deburred, and cleaned |
| Rod Bolts/Head Bolts | ARP, GM main and head bolts |
| Balancing Specs | Balanced to within half a gram |
| Oiling System | Modified Factory |
| Windage Tray | None (they shred and come apart from rapid engine acceleration) |
| Crank Scraper | None |
| Oil Pan | GM stock replacement |
| Oil Pump | Melling high-volume 60 psi (disassembled, checked for clearance andcorrected if needed, deburred, cleaned and reassembled) |
| Feature | Detail |
|---|---|
| Heads | 6X-8 '75 to '78 |
| Chamber | Open |
| Head Mods | Hot-tanked, blasted, magged for cracks, new guides if needed, exhaust seats opened up for 1.77-in valve, ported for application, competition valve job, bolt holes tapped, machined for positive oil seals, cleaned and flow-tested |
| Combustion Chamber Volume | 96-98cc |
| Intake Flow | 245-260 cfm at 0.55" |
| Exhaust Flow | 215-225 cfm at 0.55" |
| Compression Ratio | 9.25:1-9.5:1 |
| Valves | DCI severe-duty one-piece stainless steel, 2.11/1.77 |
| Valve Angles | 35-45-60 degree |
| Retainers | Comp Cams 10-deg |
| Keepers | Comp Cams 10-deg |
| Valve Guides | k-liner |
| Valve Seats | Best Gasket Viton positive |
| Rocker Studs | ARP 7/16" |
| Rocker Arms | Comp Cams roller tip, 1.65:1 |
| Pushrods | Comp Cams chromoly 0.080", 5/16" x 9.300" |
| Cam | Hydraulic flat tappet, custom ground to DCI specs by Comp Cam |
| Duration at 0.050 | 246/254 |
| Lift | 0.550/0.570" |
| Centerline | 108 degrees |
| LSA | 108 degrees |
| Installed Position | 106 degrees |
| Lifters | Comp Cams hydraulic |
| Valve Springs | Comp Cams, dual |
| Seat Pressure | 135 lb |
| Open Pressure | 320 lb |
| Timing Chain | Comp Cams double-roller |
| Feature | Detail |
|---|---|
| Intake | Edelbrock Performer RPM dual-plane (port-matched to heads) |
| Carburetor (not included) | Quick Fuel or Holley HP recommended |
| Carburetor Size | 950 cfm |
| Carburetor Mods | Idle circuit re-calibrated for application, re-jetted for application as needed |
| Carburetor Jets | Application specific |
| Fuel Pump (not included) | Holley electric 150 gph, Holley regulator, fuel line size 1/2" recommended |
| Distributor (not included) | GM HEI or MSD billet, MSD 6AL,MSD Blaster, Taylor 8mm recommended |
| Total Timing | 32 degrees |
| Initial Timing | 20 degrees |
| Mechanical Advance | 12 degrees |
| Vacuum Advance | None |
| Headers (not included) | Hooker, Hedman, Doug's, or Flowtech, 1.75", 32 to 36" long, 3" diameter collectors recommended |
| Gaskets | DCI |
Contact DCI Motorsporst to discuss your next Engine build
Call 330-628-3354
Upgrade Options
There are too many upgrade options to list. Anything you can imagine can be upgraded, from valve covers to advanced options such as fuel injection, turbos, and super chargers. Please contact us to discuss your next Pontiac engine.
One of our popular upgrade packages
- Heads: Edelbrock RPM (ported to 340 cfm with 2.19″ intake valves)
- Intake: Edelbrock Victor
- Cam: hydraulic roller cam 254 int and 260 exh duration @ .050
- Lifters and Rockers: solid roller, Harland Sharp 1.65 roller rockers
- Compression Ratio: 10.75:1
- Horsepower: 650
- Torque: 670 lb-ft
Warranty: There is no warranty or guarantee on high performance street or race engines or parts. There is no guarantee on horsepower and torque. All horse power and torque are estimates only and can vary with fuel, altitude, improper installation, improper use, and other restrictions outside of DCI’s control.