I just spent the whole weekend measuring the area around the rear deck speakers.
Some good news: You have almost an inch above the deck to play with given the stocks plastic mount ring.
More good news: The deck sheet metal isnt that thick, so if you need to cut it, its not impossible. (Please take full welding precautions as the gas tank is right below you) :bomb:
Bad news: Now this is the one that gets me. Its not really the gas tank that gets in your way for depth, its the stupid bracket around the gas tank. It robs you of at least an inch in mount depth.
From from the bottom of the deck to that bracket I got 2.9-3.0 inches. Move that bracket and you are looking at at least 3.75 inches clearance easy.
Given that that speaker has a 2.75 depth, it would seem that it would fit np, but you would have to cut the opening to make it larger like miscreant said.
iqbalinc got 8"s to fit in the back, by going up and increasing the hole size, so it can be done.
I spent a long time thinking about this and decided to go with these:
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=12138
Its a smaller 6.75 fitment that will drop into stock mounts, and should mean no cutting.
Hope this helps