Reply to "AFD Alum heads"

Kevin,

The hard block does not affect water temp, the weight gain is minimal, as you are displacing coolant, the weight gain will amount to the difference in weight between the 2 materials.

Not all Australian blocks are good ones. Most are thin wall castings identical to the blocks cast in the US. The later Aussie blocks have a different size distributor hole & aren't viable as a US replacement. Ford had a small batch (or batches) of special blocks (reports quote only 200 blocks from the first casting) cast in Australia and distributed them to the race teams, NASCAR, drag racing etc. I've read that they were cast of a higher strength iron alloy, I can't verify that. These blocks had full width bulkheads & pan rails, a bit more material around the cylinder walls, the one I've seen had siamese bores, but that was an exception, perhaps even an experiment (I used to think they were all siamese because the one I saw was). The blocks were also checked for core shift of the cylinders prior to shipment to the US so only those with the most uniform cylinder wall thickness became the actual NASCAR blocks. The rejects with too much core shift were placed into production vehicles in Australia, so a NASCAR block locted in Australia has doubtful value. The NASCAR blocks did not crack under hard use. these blocks show up from time to time used, but I've never asked anybody how much they've had to spend to acquire one.

Other "sketch" and experimental parts, including blocks, show up on the market, you'll find them on e-bay. I don't know much about these parts other than that they exist. The block must be judged by how ready it is for use (fully machined?), how worn out it is, does it address the Clevelands problem areas like the NASCAR blocks (i.e. thicker bulkheads & pan rails). Buyer beware. Just because it is a special, non production, part doesn't necessarily mean it is any better.

your block head friend on the PIBB, George