Here, check out this link. If you scroll to the bottom there is a little bit of information about using an early model body lift kit on a late model Isuzu.

Also, if you are thinking of going larger than 33" you need to consider a gear swap. I believe the 5.38's are what you would be after, but I've heard some say that our IFS cannot handle such large tires and that anything over 33" would require a solid axle swap. I think 33 is kind of the "magic number" here, as anything bigger starts to require a lot more modification.

Incidentally, I'm researching a gear set for VX's with 33's (probably 4.77 or 4.88 ratio). I know this has been proposed a number of times to no avail, but there is obviously still demand if we can find someone to supply them. There is a company called Tera that makes a 5.38 gear set and I'm hoping that they might consider making a 4.88 if we can organize enough orders for a group buy.