I would check the spring codes on the trucks. Just because the one truck is a 350 doesn't mean that it has bigger springs. The trucks could have the same springs. If you were to build a truck you could get the same springs as a 350 in a 250. The only difference is a taller lift block in the 350. To check the spring code it is on the sticker in the door jam.
Last edited by 03-blue-Powerstroke : 07-06-2009 at 06:44 AM.
Reason: added info