Here's a shot of the stock throttle body gasket. The circle drawn is the size of the 240sx throttle body opening that I ported the intake mani to. Above it is the die grinder and the carbide burr I used to do the porting. The burr was ok, but you can get ones specially for grinding aluminum that would work a bit better. They don't load up with as aluminum as quickly.
The block, cylinders and pistons were in great shape. No cylinder ridges and I could still feel the original cross hatching. I left all that alone, retapped the head bolt threads and cleaned up the block surface for the new head gasket. I also BROKE one of the head bolts on removal. I ended up welding a nut on the end and taking it out. Some material got in the threads and seemed to weld itself in.
