Just started 230 swap- wiring question

[sags]

Folks- need some help. After a few months and lots of clean up, I finally got to where I could start the 'new' motor. I swapped a leaky 230 for a rebuilt and resealed one. Started and ran for a bit but won't idle yet. Another day. But I have some wiring questions. First, see the tab coming off the ignition? Where is this supposed to connect to? The old motor had an HEI conversion but the bigger, bulkier version. Is this for an aftermarket tach? Second question, there are three wires for the solenoid, purple, black and white/green. The black wire has a big connection like the positive battery cable. Is it a safe assumption that goes along there? And for some odd reason, the cold temp light goes on and stays on when I connect the battery. Any thoughts on why this is happening? Happy Father's Day to all out there.