Titan! They're not the cheapest option, but you get to keep the bed. I had one in my '05 Sierra and had just topped it off when I was struck by a semi on the interstate and violently spun and rolled that puppy into the median. Didn't leak a drop. Immediately put one into the LBZ I purchased as a replacement. If you tow something long and heavy, it's a pain in the butt to find a diesel pump every few hours that likes a fifty-foot combo.
I am doing my homework on extended tanks. I have a 2005 LLY, crew cab 6’ bed.
I called Titan & S&B. Both had great reps who were professional, polite & knowledgeable. I flat out asked both why I should buy their product over the other. Titan boasted USA made & available on the east coast via authorized dealers.
S&B stated that they include sending unit. BIG PLUS, S&B have baffles in the tank. Specifically around the pick up and sending unit.
S&B is cheaper but are 4+ weeks out to ship. No local dealers. Shipping is free however.
Next I contacted a reputable custom shop whom I’ve used in the past. I told him my mission. He stated that he has run into the following;
1) fuel starvation when truck is on an angle. The tanks are so large/long that fuel rushes to the low point. You could have 1/4 tank and all that fuel is in the front or back on an angle/hill. S&B baffle will help prevent that.
2) Extended tanks are so large you need to re-locate FAAS or other lift pump systems.
3) Extended tanks hinder dropping transmission & transfer tank. Hence you need to drop the tank to work on transmission.
These are the hurdles I have come across so far. I will definitely go with the S&B because of the baffles . Seems like a “no brainer”