Try the website crutchfield.com. Then follow the links to car audio, speakers, it asks for year make, model. Scroll down, speakers were towards the bottom of the page. There are "featured" speakers but there are others listed in the sidebar. In my 1988 wagon with power windows I used the stock Volvo plastic grills in the front doors and the Infinity Reference 4" speakers. They come up with Kenwood's as the featured spkrs. [Infinities are best suited to jazz and classical]. I took the entire door panel off, reinforced the backside area around the cut-out with a thin sheet of plastic glued to the fiber board on the backside, drilled new holes and popped the entire assembly back. If you use original grills be careful not to break the nubs off where the speed nuts go.

http://www.sonystyle.ca/webapp/wcs/stores/servlet/ProductDisplay?storeId=20153&catalogId=100803&langId=200&productId=8198552921665805556

Cut and paste the link, I just put these in my 82 242. 5 1/4" sony's, they fit in the existing speaker holes without any cutting, they clear the window, door handle, manual window crank and sound great. I used the provided screws, drilled a smaller pilot hole through the door panel and into the door then screwed them in snug. I'll have to remove the speakers if I need to remove the door panel but I'm fine with that, it's four screws each and I have a cordless drill.

A hell of an improvement over stock or the old 4" sony's I had in there, at $80 Canadian they're well worth the money. I have pics of them if you want a peek at them installed, email me through the BB or reply with an email address and I'll send you pics. They are far from stock looking but that's not a concern for me, try finding a 4" stock looking speaker that sounds good..

FYI I have kenwood 6x9's under the rear parcel shelf with un cut cloth on the parcel shelf itself, Sony mp3 detachable face deck. It's plenty loud when I need it and nice and clear at low volume. Easy instal all around, it's the first thing I've always done in any 240 I've owned since day one. I have a 1200W amp with a 10" sub woofer in a box from an old car but with the new door speakers
and the 6x9's I don't think I need it in the 242.

Since the later speakers like this mount on the front of the door card, you have lots of room. As I write this I have a TSA1086 Pioneer 4" speaker on my desk having one of its connections repaired. It is 2 1/16 tall to the front of the tweeter. The trick is to use the old speaker chassis so you can use your stock cover. I think this was originally Jorrell's post. Use a grinder to cut the struts that support the magnet from the back of your old speaker frame. Clean up the mess and mount that over your new speaker. Just about any 4" speaker will fit, and you can put the stock grill back on the original frame. Or not, of course, depending on your taste. Yeesh, sorry, as usual I cannot get a picture to load. Happy to send you one if you mail me.
DS

There, got it, at least to the gallery.

http://www.brickboard.com/GALLERY/volvopic.htm?js_link=&id=9574

I used my initiative, I measured about 1.6" clearance. Should be able to fit most of these in:
http://www.midwestelectronics.com/categories/Car-Stereo-Speakers/4.00-Inch/