Thanks, I have added all this to my reference book
I had noticed that suffix difference on two apparently otherwise identical fuel pump relays and I was curious about what could be different. What brought all this up is that I switched to a Bosch external fuel pump from the Mustang in-tank pump I had been using. I have not yet checked the current draw on this new pump but the thing is huge compared to the Ford in-tank pump and I was afraid the stock relay would not be heavy enough. The question about a relay for an auxiliary fuse panel is for another project and the fuel pump was my big concern here. I was told by someone local that the EEC power relay was rated higher than the fuel pump relay but I was a bit skeptical that was the case and apparently it is the other way around.
Thanks again everyone.