I got some bugs that I can't get rid off, so I'll post some theoritical cases here to go elimitating them.

I have a huge concern on the Fuel System. Since my Digital Gauge havent arrive, I cant check pressure all the time.
But each time I go to the Gas Station to fill the Sucker, A huge sound of de-pressurizing comes out when I realease the cap. Is so nasty, that I place myself under the truck to see if there's something wrong, and the tank looks IMPLODE.

The bottom of the tank is arcked outside in, like when u get a Gatorade Plastic bottle with a lot of thirst and u suck the MF and bends towards the inner side....just like that looks my tank. I just replace the Gas Cap, but same result!!!!!

Any sugestions on this matter?