Stack size on a rotisserie smoker

Hello all, I'm new to the forum and in need of some professional advise. I bought a BBQ trailer a few months ago and the guy that built it installed what looks to be a knock off Cadillac cooker on the front. It's a very well built unit but it seems that he didn't know how to dial in the intake and exhaust. It's a 565 gallon tank (48x72) and it haseems a firebox the runsame pretty much the entire length of the unit (17x12x60), it has only 1 intake damper that is 8" and 2 smoke stacks which are 3" diameter and 22.5" tall. I want to run it using wood only and not the propane burner on a temp controller. The issue km having is that I can't get the unit to give me a nice light blue smoke out of the stacks. I own a Lang 84 hybrid deluxe also and I can get the perfect cook with that. I'm thinking that the stacks are way too small for the tank and the more I look know it, it looks like I need to install another couple intake dampers also. I'm thinking of switching to 6" diameter stacks and adding 2 more 6" intake dampers. Any advice would be greatly appreciated as I'm permitted now and want to start using this monster smoker for over night cooks.