Anyone done a straight axle on a Colorado/Canyon?  if so, what axle, and did you beef the frame rails any? considering a cummins 4bt swap into a Colorado, and the engine weighs about double a 3.7 I-5. I know the IFS wont handle the extra 300 pounds!  

sprintpusher,

 The colorado/canyon was not designed for a straight axle. The newest modifications that has been done to this truck is the small block V8 that has been added into the latest 2009 series.  Matter of fact the new H3 alpha and truck series all have IFS and they have widened the frame and mounts to accomidate the changes inludinge heavier springs and shocks to support the engine weight.
 Now I have a buddy who took his 04 canyon and put in a jeep straight axle and it worked also supported but he did alot of on the spot modifications.  His canyon was only 2wheel drive so it was alot easier for the swap. However not sure but my understanding with the smaller trucks, you can do the same for 4 wheel drive however, just take a rear axle off another colorado, swap out the gears for the front end and it should do the same. The axles in the rear will be strong enough to support the weight change however, you are going to have to do some on the spot modifications. One other thing you might try is the older versions of the isuzu troopers were all straight axle and they were 4 wheel drive and can take punishment so that would be another option, check the width but its an option. Remember chevy owns isuzu so that is where I got a full size spare tire for my colorado for a 6 lug. This is where the wheels came from for the design of this truck.  

Anything is possible with enough time and money. I haven't seen one yet though...