Disc brake Caliper pins/bolts sizes????? Where to buy???

I see what you are talking about now and they are right. These pins are only listed for B bodies because A bodies never got them. You need that much pin so the caliper can slide in and out. The pin itself bottoms against the caliper bracket and the caliper is captured by the head on the pin. The only thing I see that needs attention is the lack of dust boots between the head of the pin and the caliper body. If they are not there the pins will rust and the calipers will stick. Make sure the pins and the slider face on the caliper bracket have a good coat of lithium or high temp grease so the calipers can slide.....