carbureted 5.7 - 6.1

Stay away from the 03 truck motors as they are known for weak valvesprings. I would look at a car motor as all the accessories are mounted low and would look much nicer. But really any motor will work. Keep in mind though that the 03-05 truck motors do not have MDS and there for would be one less headache to deal with. The 06-08 Truck motors and all the car motors have MDS. It's not really an issue but for piece of mind would require changing 4 lifters and requires removing the heads.although not much of an issue but it does pose a slight problem. That is assuming the lifters need changing. I am not 100% sure they need to be removed. As I don't have an MDS motor. If you find an 09+ motor it has variable cam timing and I don't know of anyone that has made it work in a swap type setup. But that could change if someone does it and I'm sure seome out there is working on it. It's just info available to us as of yet.