Heater core bypass valves?

[lil_Blue_Ford]

Lol...

Mine were cackly....then when i pulled them out i seen the tops of them were totally dried out and sunbaked

They were an oddball size originally, you need to buy or make brackets to hold common speakers. I was going to put new speakers in there on my 88 but I might just stick a couple tweeters in the dash and put some decent speakers in the doors.

 

[SenorNoob]

I've got a pair of these in mine:
Scosche HD4004

I can't see how anything larger can fit...

Edit: Maybe a 4.5in if you turn it right.