Stock Toyota Radio Interchangeability

I have a 1990 Toyota Pickup truck. It is the basic 2 wheel drive, 4 cylinder drive model they made then. They didn't give them names like "Tacoma" in '90, but it is very similar to the Tacoma, especially around the radio. The original am/fm cassette radio is still in the truck. It is about double the height of a standard car radio. I want to upgrade to a later Toyota am/fm/cassette/single cd radio, but I don't know what will fit. I read in the description on one eBay auction that: "Toyota radios come in two basic sizes: 7 inches wide and 7 7/8 inches wide. This one is (7 inches) so please measure your current radio to make sure!" Is this correct? Can anyone tell me more about the interchangeability of Toyota radios? Would a radio from a 2001 Celica GTS be a direct fit? It looks the same, but this claimed difference in widths makes me unsure. Thanks!

I can't say if it would be a direct fit or not, as you'd have to fit it up and see.  I doubt it will be a clean looking fit.  The width issue concerns the outer trim mostly.  But, at least one thing would probably work - Toyota has used the same audio connectors on the back of their radios since 1987.  So at least you SHOULD be able to plug it in.