I don't know where the idea that stock GMC rockers were not good enough. There were no roller rockers in the 60's and I don't remember having any problems. We used the set with aluminum stands and welded the rockers down the split on top and tacked them on the under side. I still have a set on the stock shaft. Even with roller lifters we normally didn't have over .550" lift total. Think about it the push rods were 2" longer than stock and couldn't take it. Springs were good for about 6500 max if drag racing and lower for the lakes. Our problem was going thru valve guides since the rocker tip pushed the valve sideways because of the lift. I didn't have roller rockers until 1991 when I designed and made my own. As I remember only 3 guys had them on the west coast. Don Ferguson made his first set right at the same time I was doing mine and his copyed Joe Fontanas. Mine were a little different at 1.63 to 1 and have never failed.
I now have a set of Joes 1.75-1 and look to go over .700" lift. Gheesh when I got over .620" I thought it was phenominal for a GMC. 50's knowledge was trying new stuff and breaking it to know the limit....Just like today. To bad we can't go back and Howard J. on how much he broke going fast.
Hey have some fun, built what you like, and some day my kids will throw all the "junk" I've got hidden.....but don't count on it.
JD
