I bought the GMPP 170cc Vortec heads and it says to use self aligning rocker arms?? I dont know what those are.. I have standard sbc 3/8 magnum roller rockers from my old 882 heads.. will they work??

 

Self aligning rockers have nubs or some sort of thing on the sides of the valve stem end of the rocker to keep it aligned over the valve. The pushrod hole is round and larger than the pushrod.

The only way to use non-self aligning rockers is to use guideplates. If you have screw-in rocker studs, you can replace them with guideplates and guideplate rocker studs.

 

If those are the stock replacement ones, then you need to do some work on them, anyhow, as the retainer meets the valve guide seal at a little over .450" of lift, at least on the ones I had.

 

I have pressed studs... Ok so Im assuming I cant use my roller rockers seeing as how they have no "nub"

 

Good excuse to have the press-in/pull-out studs removed and the heads machined for proper screw-in studs. Might cost you the same or more than self-aligning rockers, but you'd have the added benefit of no longer having pull-out studs.

 

While your in there put in some push rods guide plates. They go under the screw-in rocker studs. After you get some hardened push rods, you will be able to run regular roller rockers without the self alignment.

 

CNC-motorsports has SA rockers with a roller tip, in either 1.5 or 1.6 ratio for a paltry $80. Most likely that's cheaper that machining for guideplates.

You'll still want to grind down the valve guide for higher lift.
And pin your rocker studs, or pull them and put in threaded ones.

Personally I pulled the press-in studs myself, and tapped it for Mr gasket part number 76 I think it was, the non-collared thread in rocker studs - $26.
Then bought the cnc motorsports SA rockers.

EDIT: Your current cam in sig is too weenie to require you to machine down the guide boss as is.

 

That's what I was getting at - see my first response.

 

Well summit actually let me return my old non self aligning ones in return for the new ones plus the differance.. turned out to be like $40 so thats the route Im going.. Im gonna upgrade the heads again later on when I get home from Iraq along with the cam and still considering a stroker motor.. but thanks for all the advice guys..