Isky Ductile Rockers

[AMXguy]

I just bought asset of like new Isky adjustable ductile rockers with  all the hardware for my 440 build.

What I am unsure of is how they space properly.  they have the stock mopar hold downs but the spring pressure between them is so firm there's no way it won't wear the hold downs in fast order.   it's so tight it takes some effort to rock the rockers. 

I looked at the  Dvorak Machine mopar hold down spacers and that seems like a much better idea.  is this a good plan?  something better? 

Also is there anything I should know or look for with these rockers?  I've used Crane before but these look a little different.
 

[1 Wild R/T]

I use Hughes hold downs, I also place at least 1 shim between the rocker & the hold down & 1 shim between the rocker & the spring.... Some guys change the springs for solid spacers....  I have lighter springs I was planning to use but a few old racers tell me the heavy springs are better...


You need to check the alignment of the hardened pad over the valve, often the rockers need a quick modification in a lathe to properly center the pad... I usually cut .050-.065 off the side of the rocker that contacts the hold down, that allows you to set the contact with shims....

[AMXguy]

I just looked at those and they look just like the Dvorak ones.  probably the same.   

So you use those and the thin shims?   do you think the shims are needed, provided the rocker pad lines up, or do you use the shim just for a wear reduction device?   I can get my rockers machined but it will be a PIA.  the shim will just make it worse I suspect.

[1 Wild R/T]

I use the shims because I feel it improves the contact pattern, lots of ductile rockers are run for hundreds of thousands of miles without them..

[larry4406]

I had these in the early 80's. I used valve spring shims (washer like but bore matched the rocker shafts). Then ground the tabs on the OEM spacers. Grinding of the OEM spacers and shimming allowed me to center the rocker on the valve tip by eye. I did not use springs