I have a set of vortech heads I am putting on my 350. When I take them to the machine shop, what do I need to have done? Do I need to go with bigger valves? And also, for the extra expense, are roller rockers going to make that big of difference? I am not going to race, just building an iroc with a little get up and go to play in.

Thanks.
Kevin

 

First, welcome aboard.

2nd, "Vortec".

Now, your question. A recent Chevy High Performance mag had an article on just this topic. Basically, bigger valves don't help. Manley Pro Flow-style valves with the cut-back stem may help, though.

Stock, those heads have very poor valve lift potential. The springs are wimpy, retainers heavy, guides stick up too high. Have the machine shop trim the guides down (nice time to go to possitive-seal type stem seals). Put nice performance springs & retainers on when it goes back together.

The rocker studs are press-in - also known as "pull-out". Have them machined for screw-in studs. If you want, you can also have guide plates installed, then you won't need more expensive self-aligning rockers.

 

So what kind of heads would be better? I also have a set of 441 and a set of 882. If I have the vortec heads worked with nice springs, etc, they should be fine? Also, what about the rockers? Roller or not?

Kevin

 

The Vortec heads will out perform these older 441 type heads
hands down. No comparision. The stock vortec retainers are light weight and strong. The vortec valve seal is high quality positve seal. If you use the right cutter to shorten the guide boss, you can Use them both over. New hi perf replacement stock diameter valve springs are highly recomended.
The pressed in studs are fine for moderate street lift and spring pressure, but if the budget allows spring for the screwin studs and guideplates.

Don't even think about passing over the Vortecs for your 882's
unless you want to be at the "back of the pack".