I have 2 new sets of Thomas magnesium high lift rockers for a GMC. I did put a set on #1 on a shaft once to check them out. Just putting them beside the stock ones you could see a difference on the short side...Got it yet..."short side" probably work with the stock skinny push rods but with larger diameter and a high lift cam you would need to hog out the push rod hole and I didn't want to do that. The do have a stock appearing tip and also do not come with adjusters so the stock need to fit into them...JD
