I just obtained a set of race ported (they flow 271CFM @.500 lift) vortecs from a friend and I want to have screw in studs, guide plates and install regular valve springs so I can run a decent cam with normal (ie: AFFORDABLE) roller rockers. What kind of machine work needs to be done? Can't I install the screw in studs myself with a tap? what valve springs do I need to buy to run this setup on my firebird with a Comp Extreme Energy 284 (.507/.510)?? Somebody with a similar setup please make some suggestions....I'm already running vortecs right now but I'm looking to run DEEP 12's on the motor with these ported vortecs. Actually I wanted some cam advice too....should I stick with my 268 and install 1.6 rollers (they flow peak @.500 lift is why) or go with a 274 or 284 extreme comp cam? thanx
chris

 

There really is no point in going way over .500" lift. Stock they top out there, and you said they maxed out flow there as well on the set you have. I have heard, and read that Vortecs don't respond well to bigger valves either. I would go with a bigger stick. My specs are below, and I would go one size bigger with your heads if possible, if not then at least the same. You really can only gain from duration, once the .500" mark is hit. As far as springs, run those that are recommended by the cap manufacturer. This is your best bet to make sure they won't fail, or be the wrong ones. You could even find out the specs of the springs, and find some from a different company that match, and maybe save some money. There is a tool made as a guide to drill and tap your own holes for studs. The down side is you need the top of the "pads" milled down an equal distance to the thickness of the hex part of the stud. if you run guide plates, more will need removed. It cost me $85 to have mine milled and tapped, and $30 for ARP studs. If you plan on running a roller cam, and the proper springs, I would seriously consider running studs. The pressure of the spring will be the deciding factor in the stock studs pulling out or not, assuming there is no binding. I am kind of anxious to see how your car runs after those heads are put on. I would have loved to port mine some more, but I was leary of going to far, and messing up the flow characteristics.

 

I would keep the 268 cam and get some 1.6 roller rockers.