Speaker sizing question

I did a search on this topic, but nothing came up that answered my question, which is this:
The two rear 4 X 6 speakers in my '83 SC are both toast (literally). I went down to my local stereo place and picked up replacements. The problem is that they are too deep. Has anyone else had this problem? What is the max depth I can use? Si athere some other way to replace with non- OEM speakers?
Any suggestions would be appreciated!

Magilla Gorilla
'83 SC

Just did my rear speakers and used Infinity 4652cFp they are two way with a rating of 40RMS or 120W they sound great. They went in the standard opening and where OK on the depth.The only thing is that they do not come with speaker grills, I kept the old ones and riged them to fit. Make sure if you go this way that the grilles that you use do not impede with the up/down movement of the speaker if so you can just cut the plastic to fit. Circuit City 100.00
Email me if you have any questions.
GB83SC

Huh! I bought Infinity 4652cfp's, and they were too deep! Is the panel under the rear deck flexible? Should it be at an angle (deeper towards the front than the back)?

If you remove the back panel it can be adjusted to fit.
E-Mail me if you have any questions.
GB83SC