i have a 2003 gmc sierra 1500hd crew cab reg box but it only has a 90L tank so its a giant pain in the A$$ so i was wondering if anyone has ever done a swap i was thinking of getting one out of a duramax preferably 120L or if anyone knows of a decent slip tank that goes underneith the truck? and if my fuel pump bucket will fit in the duramax's tank?

 

well swapping to a duramax tank wont really help because the size of the tank is based off if the truck is a long box or short box the reason is due to the position of the axle. also the internals of the tank in a duramax vs gas will be different there is no pump in the diesel tanks and for that i would question if the mount on the top would be the same. the only solution i could come up with if i was in your position would be a

Titan Fuel Tanks

possibly give them a call and ask if they could make a gas one for you

 

I was lookin into those but I'm not into spending over a grand on a fuel tank

 

on the older turcks i think they held more... like our 1500 burb had 25 gal take my 2500 has a 39 gal tank..

 

transfer flow. they are not cheap, but very very well made and worth it. (plus they are not made of plastic) we have had them in our past 2 duramax trucks. gas applications available as well.

here is the link