1) Pair of 1.8L heads, 38 x 48 valves, double valve springs, with a deep relief for the cylinders. They've got some sort of thermocouples where the CHT would normally be. Exhaust ports have been machined oval to accommodate the matching exhaust stubs.
2) Pistons/Cylinders: pistons are 94mm Mahle's with a pretty good crown to them and valve reliefs cut into the tops. There's a part number printed on the cylinder base "24 503 WR 10". The cylinder tops have ridges to seal better against the head.
3) Custom header is a 4-1 style with 41mm ID primaries. It looks like the muffler is a recent addition as it's only tacked on, and there's a short intermediate adapter. The four primaries are a slip fit into the collector and are not welded (yet). The headers use separate exhaust stubs that fit the round ports found on the head. All the welds look like TIG, and it's carbon steel. I am not 100% sure the header is specifically designed for use with these heads, but the stub adapters match the headers.
I'd like to sell all together as the exhaust stubs match the heads, and the pistons also match the heads. As mentioned in the other thread, these were Chuck Forge's spares, and his car was quick! SOLD
thanks,
Carl