i just re-built my stereo system, and the front doors came stock with 6"x9" spearkers, and the rears were 5. 25" ones. Yes I too made the Infinity system and It has nothing on the new system. I choise the 1. 5 DIN to replace the factory radio, I wanted a full height radio to fit back in the factory space with no spacers or adapter needed. Their isn't a large selection of 1. 5DIN to chose from, I went with the Pioneer P77. It works great for me and look very nice in the truck. I also installed a 12 disk cd changer under the back seat, along with a 500Wamp. For speakers I went with 6. 5" Polk Audio component speakers in the doors, and 5. 25 polks in the rear. If I had to do it again, I would use the 6. 5" speakers for both places. I am very pleased with the sound and performance of the new system, the radio makes the truck look new or more up to date. The install was easy and I did buy thru Crutchfeild, great place to do business.