Hello, I am in the process of swapping a 5.2l Magnum and 46re into my 1989 D100 on a limited budget. The fuel tank situation has proven to be difficult. The factory 89 tank uses some wierd wedge clamp style sending unit and i dont trust its condition to try and convert the pump to a higher flowing one and you cant get a replacement anymore, not only that but i would have to buy and external regulator to loop the fuel back to the tank. I do have a Tank that came out of a 1992 D250 cummins diesel truck. The dimentions of the 2 tanks are 99% the same so it will bolt right in my truck, and pump/sending unit i need from the newer 2001 ram drops right in the 92 tank and the screw cap secures it. My question is if there is any reson why i should not use a diesel tank for gas in my build?

 

I would check how far down the gas pump goes into the tank..... also make sure it has the connections for the evap system. (though I am not sure if the diesels used that or not.....) aside from that, clean it out good, and make sure the filler neck for gas fits properly, and it should work.

 

What year motor is it(2001?) and do you have any of the evap stuff for it? I believe the gas cap on a 89 is sealed so you will need the evap stuff to vent the tank. Or at least some of it.