I put a under frame tank in on my 52 ,I got it from a company called Tanks inc. comes with the straps .I had to build some brackits and do some fab work but when don't we have to.My filler comes out of the bed maybe 10 inches in front of the tailgate I also used there stainless trim around the filler neck the whole thing is flush with the bed wood looks good. The model I got is for costom trucks .

Pete