Ive been using this pair of 062 Vortec's for about 10 yrs now an found some interesting things. I ordered them new an installed screw in rocker studs an did a quick bowl blend to them when I first got them. Then I decided to do some upgrades to my 350 an took some time to cc the chambers an intake runners an exhaust. I've posted this before but new untouched iron Vortec chambers are 62cc not 64. This could make a big difference if your using a compression calculator. I decided to cc the intake runners this past weekend an there not 170. All of the runners were in the 167-168 range. Not that it makes a big difference. Exhaust runners were 57-58cc not 60. The chambers I cut most of the square boss next to the sparkplug hole, rounded it & lower it. I was able to get the chambers to 64cc. Worked on the bowl a bit more reshaping the valve guide boss then cut on the runners getting them to 172cc. I didnt enlarge the head to intake manifold opening worked mostly on the pushrod pinch area. Took me a few days cause after a few hours I tend not to see things. I love to be able to flow then on a bench but Im strapped for cash.