 |
|
 |
| Steve describes his Aussie 351C heads on his 302 engine Goose. |
| In the image below, you see two things indicating an Aussie head. First, at mid left, note the square casting around the head bolt hole. Second, at bottom left, note the hook in the casting at the bottom left edge of the casting. These are the most obvious things that one can look for and see, while the head is on an engine. In the upper left, you can just make out the casting date. In this case, it is 29H4 or the 29th of August, 1974. The Aussies date code differently from the US. Here, it would have been 4H29 typically. |
| These Aussie closed chamber heads have had the 2.19" intake valve installed, which has also lowered the volume of the chamber due to the increased valve head size. At the top of the following photo, upside down, are the tell-all marking for Aussie heads. On one intake port runner you see the ARD1AE casting mark indicating an Aussie head, and on the second runner you see the part number 6049-AB. The most important thing about this number is the -AB. Steve also received one -AC head, but the chambers were even smaller! (That head was returned.) The -AC head was a later head by about 4 years if Steve remembers correctly. If these casting numbers and or dates do not match up, then be certain to have the chambers cc'd for volume in order to have a matched set of heads. Astute viewers will note the plugged water passage on the end of the head surface. This was done as these will be run on a 302(or 351W), which has the water passages on the intake face, requiring the chamber face passages to be blocked off. To use these on a 351C in the future, remove this plug, and plug the intake face hole. |
| In addition to the larger stainless valves, the heads were machined and tapped for screw-in studs. I believe that the exhaust seats are now the hardened version. The intake valve seals are the "perfect circle" style of positive seal, which requires slight machining on the casting. Exhaust seals are standard umbrella seals, to allow sufficient lubrication of the exhaust valve guide to prevent galling. Bronze guides were installed. By Steve�s choice, the valve bowls were ported, but not the runners. The bowl area is the area that can use the most attention. Port the runners, and you are getting back into the problem with 4V heads... too much cross section ! These ports will do fine the way they are. New valve springs, retainers, and keepers were installed to match the cam Steve is installing. Very important to check for spring bind and proper clearance here, as all springs and hardware are not the same ! |