I was wondering if someone could tell me the differences between a F450 and F550 in reg cab 4x4 configuration. I had an f550 4x4 once and I know it has the monster dana 135 rear end and I think the F450 only has an 80 in it. But are the frames the same? Can I make a 450 4x4 into a 550 4x4 with just spring and rear end changes? I did try and search for this info but couldnt find it. Thanx Nick

 

I havent owned too many fords but boy I thought this question would be well known to guys into Fords. I am going to bid on a 2001 F-450 with a 7.3 at an auction tomorrow to replace my 1994 3500hd chevy that has a gas motor with 300k miles on it, but I would like to have the GVW of a F-550 as my chevy is a little more then the F-450(15000lbs for 3500hd vs 14500lbs for a F-450, both these trucks have the big tube dana 80 while the F-550 has the Dana 135 I think) Just dont know if the frame thicknesses are the same between the f450 and f550 as the rest I think would be easy....Someones got to know somethin about 450/550 Fords on here.