490 HORSEPOWER 'OUT OF THE BOX!'
EARLY 253-308 CARBY HI-PORT ALLOY HEADS
P/No. ABHA 308-3 (ASSEMBLED)
The ultimate basis for power generation on pre-injection Holden V8 engines using “RED” style intake manifolds and exhausts systems.
Raised intake port design radically improves “as cast” flow up to 40% over standard heads. Redesigned water jackets allow individual porting shops ample scope for further improvement with intake flow figures around 260 CFM possible with radical porting and 2.02” valves.
Yella Terra cast alloy intake manifold spacers are available to reposition manifold face to match revised port location. Exhaust port location matches standard performance exhaust flanges.
“Dash 3” heads are available as bare heads with semi finished seat inserts fitted ready for cylinder head specialists to perform further modifications and finish seats to their preferred specifications.
Fully finished assemblies with “as cast” ports are also available featuring 21-4N Stainless 1.940” intake and 1.600” exhaust valves, high lift double springs and chrome moly retainers. These assemblies make an excellent performance street combination with power potential of 490 horsepower out of the box.
Yella Terra “Dash 3” heads are machined for 7/16” screw in studs ready to bolt on stud rockers or Yella Terra platinum race rocker systems. The alloy castings offer a 50% weight reduction over standard cast iron heads.
TECH SPECS:
| Material | AS 601, 356-T6 Heat Treated Aluminum |
| Minimum Hardness | 88HB |
| Weight | Bare 10.8kg - Assembled 12.7kg |
| Combustion Chamber Vol | 56cc |
| Deck Thickness | .575” |
| Inlet Port Dimensions | 1.980” High x 1.200” Wide |
| Exhaust Port Dimensions | 1.525” High x 1.170” Wide |
| Inlet Valve Size | 1.940” Min |
| Insert Size | 2.100” X .250” |
| Exhaust Valve Size | 1.600” Min |
| Insert Size | 1.625” X .250” |
| Spring Pockets | 1.50” Dia Min |
| Material Thickness | .420” |
| Installed Height | 1.760” with Standard Length valves and .60” Spring Cup |
| Valve Angle | 5.1 Deg |
| Valve Position Inlet Valve | Standard Position |
| Exhaust Valve Position | Standard |
| Port Location | Inlet Raised .600”, Exhaust Standard |
| Spark Plugs | Machined to accept tapered set or washer seat spark plugs |
- Rocker pads drilled for 7/16” studs
- Use YT 5020 or YT 5010 roller rockers
To order this product, please call Yella Terra (03) 9555-5522 or use our Enquiry form and we will contact you to confirm shipping and payment.
