Yes that was my truck you saw it on and Mike should be able to get you the part. The part Number is FLM 10600 it sold for 17 + shipping.
I removed it from my FLM chassis and installed it on a my G3. build. So it pretty much interchangeable between the GM and FLM.. The GM requires some new drilling to fit and will limit you to a 44 spur gear though..
Hope that helps..
Have a great one.