I have a 83 Blazer with a 6.2 diesel in it and i want to add steel dual side tanks to it, not the plastic tanks. I see a bunch of threads about dropping the side tanks in favor of a rear mounted tank but not the other way around. My question is will the 20 gallon tanks fit the short wheelbase (exhaust not whitstanding) or am i stuck with the 16 gallon tanks? And if the 20 gallon tanks will fit which models can i steal the tanks from? I see some 20 gallon tanks for sale on e-bay but what model truck should i buy them for? (Most trucks listed for the 20 gal tanks use different part numbers so there must be some difference in the tank from model to model and year to year.) Thanks guys.