I picked up some relays today, and ended up getting SPDT relays/sockets since they were dirt cheap ($2). They're exactly like the standard R51 automotive relays I've seen except for the 87a contact for normally closed circuits.
Now, the only question I have is this:
On a R51 SPST relay, the ground (black) is on terminal 85 and 86 goes to the switch. On the relays I bought (SPDT), the tabs are reversed; ground is 86 and 85 goes to the switch. Does that sound right? That's how they're lined up when putting the socket on... If it's not right (and 85 really IS my ground), I can just swap the pigtails around. But I'm not sure if it's supposed to be this way or not...