I have a set of ported 416's with 2.02 and 1.6 valves. The valves have been de shrouded and the chamber size is 62 cc. I have screw in studs and I'm in the process of milling the stud bosses down .370 so i can run adjustable guide plates. The only thing is I don't know how to go about drilling out the factory guide slots in the heads so I can run the guide plates. Any info would be appreciated. Also I am running a 60122 voodoo cam with 340# springs. (screw in studs)

 

http://www.summitracing.com/parts/cca-4710

 

That tool only elongates the slot, it doesn't make it any wider. When you move to guideplates you need it basically "opened up" so the guideplate does the side-to-side location instead of the pushrod slot.

I suppose you could do it with a die grinder and appropriate cutting bit and just "waller it out!" a little. I've always left stuff like that up to the machine shop, but there isn't much you can do wrong in that area of the cylinder head unless you are a doofus and break into the side of the intake port. You're pretty far from any water passages in that area.

 

True dat... too late at night for me I guess. Nto paying good enough attention.

Yup you can just drill em out. That's all most machine shops are going to do; pretty crude generally. No water (or anything else) anywhere near there. Closest thing you can break into is the intake port itself.

 

Thanks for the input guys. What do you think about lunati's voodoo roller rockers? I haven't read too many reviews. This is a street car and I'm trying to make it as reliable as I can.

 

You can try them out, if you like. I haven't used them myself. Usually you find that somebody else is making the rockers for them anyway. Wouldn't be surprised if that was the case here.

 

Well from what i've seen from Lunati they have very good quality. The voodoo cam I'm running likes to rev. It has great power from 3000 to 6500. I shift at 6200. As the engine sits with the stock rockers the valves won't float. I have matched the springs to the cam very well. I want a light rocker arm that won't break or cause valve float. I'm not set on the lunati rockers but they have tested them to over 100,000 miles without failure. This is mostly a street car that makes about 20 1/8th mile passes a year.