Dragon Slayer Series Cylinder Heads/26°

DS 320™ and DS 365™
• Latest Additions to the Dragon Slayer Series
• New and Improved “As Cast” Intake and Exhaust Ports
• New 320 cc Intake Port Flows Over 370 cfm
• New 365 cc Intake Port Flows Over 392 cfm



The new BRODIX® DS 320 and DS 365 big block Chevrolet compatible cylinder heads are the latest additions to the Dragon Slayer™ series. These heads require no porting, making them the most powerful heads in their class, and are available with 320 or 365 cc intake ports. These heads also accept standard pistons, intake manifolds, and rocker arms.

Package Heads

Facts and Related Components

• PS CB:
Valve Bowls Blended

• PS MI:
Match Intake Port to BRODIX MG 2001

• PS Valve Job:
Competition Valve Job

• Intake Valves:
2.250 x 5.218 o.a.l. – BR 81040
(DS 320 Standard Package)2.250 x 5.318 o.a.l. – BR 81140
(DS 320 Spring Upgrade)2.300 x 5.468 o.a.l. – BR 81241
(DS 365 Standard Package)2.300 x 5.568 o.a.l. – BR 81341
(DS 365 Spring Upgrade)

• Exhaust Valves:
1.880 x 5.394 o.a.l. – BR 81038
(Standard Package)
1.880 x 5.494 o.a.l. – BR 81138
(Spring Upgrade)

• Valve Springs:
1.550 Roller Valve Spring – PAC 1941,
255 lb Closed, 610 lb Open,
1.950 Installed Height,
.700 Maximum Lift (Standard Package)1.625 Roller Valve Spring – PAC 1224,
250 lb Closed, 745 lb Open,
2.050 Installed Height,
.800 Maximum Lift (Spring Upgrade)

1.645 Roller Valve Spring – CC 947 or CC 948,
315 lb Closed, 915 lb Open,
2.100 Installed Height,
.850 Maximum Lift (Spring Upgrade)

• Retainers:
1.550 10° Steel – TR 752
1.550 10° Titanium – MA 2398 BR
1.625 10° Titanium – MA 23640
1.645 10° Titanium – MA 2001

• Valve Locks:
10° Jumbo – CC 611

• Rocker Studs:
7/16 – BR 716L, AR RRS-4I

• Guide Plates:
3/8 – CC 4806

• Valve Seals:
11/32 – US VS529V (1.625 Valve Spring)
11/32 – US VS485V (1.645 Valve Spring)

• Torque Heads:
70 ft-lb

• Torque Rocker Stands:
40-45 ft-lb

• Intake Gaskets:
BRODIX MG 2001, COMETIC C5428, FEL-PRO 1252-3

• Head Gaskets:
4.310 – FEL-PRO 1027, COMETIC C5432
4.540 – FEL-PRO 1017, COMETIC C5433

• Exhaust Gaskets:
FEL-PRO 1411, COMETIC C5429

• Head Bolts:
ARP 135-3606, MANLEY 42192 Bolts / 42102 Washers

• Head Studs:
ARP 235-4702 (12 pt)

• Accessory Bolt Holes Are Drilled

• Spark Plug Starting Points:
NGK R5671A-10
For Alcohol
NGK R5671A-9
For Racing Gas

• Spring Pockets:
May Not be Cut Any Larger
or Deeper Than 1.625

• Valve Angle:
26° and 4° Intake
17° and 4° Exhaust

• Angle Milling:
.0066 in Per cc

• Flat Milling:
.0050 in Per cc

• Angle Machining:
Available Upon Request

• Dowel Shift:
Not Available

• Pushrod Slots:
Standard

• Stud Girdle:
Standard, BRODIX 1230

• Rocker Arms:
Standard

• Lifters:
Standard

• Pistons:
Special

• Pushrods:
Check Pushrod Clearance With Head
Installed on the Engine Block
Before Final Assembly

• Intake Manifolds:
BM 2000 / HV 2001

Flow Chart cfm @ 28″ H20

Part Number Valve Size 0.200 0.300 0.400 0.500 0.600 0.700 0.800
DS 320 2.250 Intake 162 226 283 339 368 370 371
1.880 Exhaust 106 145 179 210 234 258 272
DS 365 2.300 Intake 160 223 287 328 359 379 393
1.880 Exhaust 106 145 179 210 234 258 272

Basic Easy Order Numbers

Part# Easy
Order #
Port
Vol.
Cham.
Vol.
Int/Ext
Valve
Spring Seat
Pressure
Spring
Diam.
Ret.
ST/TI
Per
DS 320 Bare
2320000 320 119         1
DS 320 Pkg
2321000 320 119 2.250 / 1.880 250 1.550 ST 1
DS 320 Pkg 2321001 320 119 2.250 / 1.880 250 1.550 TI 1
DS 320 Pkg 2321002 320 119 2.250 / 1.880 250 1.625 TI 1
DS 320 Pkg 2321003 320 119 2.250 / 1.880 315 1.645 TI 1
DS 320 Pkg 2321006 320 115 2.250 / 1.880 250 1.625 TI 1
DS 320 Pkg 2321010 320 110 2.250 / 1.880 250 1.625 TI 1
DS 365 Bare 2320001 365 119         1
DS 365 Pkg 2321013 365 119 2.300 / 1.880 250 1.550 ST 1
DS 365 Pkg 2321014 365 119 2.300 / 1.880 250 1.550 TI 1
DS 365 Pkg 2321015 365 119 2.300 / 1.880 250 1.625 TI 1
DS 365 Pkg 2321016 365 119 2.300 / 1.880 315 1.645 TI 1
DS 365 Pkg 2321019 365 115 2.300 / 1.880 250 1.625 TI 1
DS 365 Pkg 2321023 365 110 2.300 / 1.880 250 1.625 TI 1