I would venture to bet 90%+ people on this do not check installed heights.

 

more like 98% lol. I dont take it to the borderline of the valve springs. Most of my cams installed were my 231/237, T2's, ms3;s, ms4's, 224's, 228's,220's and few others my cam only has 598 lift and i have 650 lift spring so wont effect me.

 

I actually ended up going with the Si5 Cam same specs as yours and the patriot golds. How do you like your setup? I'm having the heads milled .15 thousandths and I hope my ptv is okay, speed inc said it'd be fine though.

 

Why would you hope for something like ptv to be ok? Why dont you measure it, then see how much you can safely mill? Doesn't that make more sense?

Just because you have a 650 lift spring and you have a 620 lift cam doesn't mean its ok to just throw them in there because you think you have a built in "safety zone." With the aggressive lobes of some cams, matched with a fairly high powerband and rev limiter, valve control can get very crucial. Not only that, you could be putting undue stress on the spring, causing it to break and costing you an engine. I truly believe that valve spring failures would be virtually non-existent if people took the time to set them up correctly. And I'm not saying that running a spring thats rated to handle more then the lift your cam has is a safe way to go.

 

I wish I could but I have nothing to measure it with now. Heads are at the machine shop I'm going to end up not having anything cut on them just to be sure.

The machine shops doing to springs to make sure they're the right height. I dont have the tools for it so I'll just pay someone to do it.

 

I'd stick with PAC springs but thats just me.