Unless you have the engineering background to consider all the variables involved in substituting non-stock parts for what was developed specifically for the vehicle, you're creating a lot of liability for yourself, and creating a potentially deadly hazard to everyone who has to share the road with you- - - - -and yourself. A modified vehicle- - - -particularly one the size of a big truck- - - - -is an ambulance chasing lawyer's wet dream. Modifications might seem like a good idea, at least until you're the guy on a witness stand explaining why you ran over that SUV full of kids, driven by a soccer mom.
Jerry