I installed a set of Comp Pro Magnum roller rocker arms on my 470. The Comp spec. on the side clearances between rockers is .030" min. How is this meant to be measured? Is this measurment the overall play for the two paired rockers and the spacer in between the holddowns or is it between each rocker, spacer and holddown? Or something else? I am not clear on how this measurement is supposed to be taken as the instructions didn't specify. However, no matter how I take it, there is no way I can get an .030" feeler gauge anywhere in between any of them. About the most I can get is .020" whatever way I measure on a couple pairs of rockers. Most are about .015".

Personally I think .015 is fine for steel rockers

Gus

I agree w 4 gear

You may need to grind the rocker arm bolt spacers or rocker arms sides to get the clearances they want.
Do it now instead of later, don't wish you had before finding out the hard way they needed that .030 total (not between each part ) between the rocker arms, spacer and between the rocker arms and the hold downs
I've had to do grind all of those parts to get the clearances needed to race with and not worry about any valve train failures

I agree that .015 total is plenty. If you love to run no oil to the heads (and by that I mean 20 pounds of oil pressure at idle with a standard volume pump) you may when issues with them at .015 and I've run my personal stuff at .010 without issue. You just have to be careful.

.015-.020" to me sounds like enough. You don't necessarily have to grind anything. Usually you can shift the hold downs left to right enough to even out the clearances.

I have these rockers and .015-.020 is what was recommended to me and it seems fine. With these rockers, there's quite a bit of clearance between the hole in the holddown block and the fastener, which makes it a hassle to hold the clearances when installing them. So what I do is use some horse shoe shaped steel shims and put one of these on the shaft for each pair of rockers as I'm tightening the shafts down. Seems to work ok.

shim

I shoot for .015-.020, which imo is plenty.