realy GMs dont impress me much anymore. There are alot of horror stories related to them and such. The parts percentages does pose and interesting throught train. I know that i have to wait to for parts vary often when i order stuff for my f-150. I know the 4.9L is rare but its not rare enough where places just dont stock parts. whith that train of though it might be becouse the 4.9L is just so tough its not cost effective to stock parts all the time...