I have received conflicting information as to whether or not 6 3/4" speakers will fit in my 2000 GMC Sierra Pickup. My factory components are 6 1/2". It seems to be a case where some places say only 6 1/2" speakers fit while others say 6 3/4" also fit. I do not really want to modify the opening because I may want to replace the original speakers when I sell the truck.

I am looking at Polk Audio db6750 but even Polk Audio can't say for sure if their speakers will fit. I guess the best way is to remove the door panel and measure?