Cruising home last I looked down to see the oil light on & no pressure on the gauge. Foul words were muttered. I continued to drive about a mile or two to a safe place to pull off. Temp & power were normal. Checking the engine, oil level normal, no leaks. I hoped the gauge failed. On restart I noticed a higher idle and lifters a little noiser. I'm thinking this means the oil pump failed.
The tappets have been noisier lately, I intended to adjust them this weekend. Also, the engine didn't have as much power uphill just in the minutes before the failure. Otherwise, oil pressure had shown normal, running normal.

My questions are: 1. Have I analysed right. 2. Have I done damage. 3. Can I change the pump without pulling the engine.

It's a 1973 1800es w/ FI, Pretty much stock. 190,000 on odo. Good compression.I don't know full history, but I replaced cam & gears a year ago. I saw that the pistons were 30 over so there was a rebuild sometime. I replaced distributor about 2 years ago. Don't know about crank.

I seem to remember it's hard to get the pan clear of the pump from underneath. I expect I'd have to raise the motor off the mounts. Will the trans support be removed?

Thanks for any advice, Tim S.