pedestal shims, think this is too many?

itsell

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So I'm installing some Crane Cobra 1.7 Roller Rockers on my AFR165 heads, The OEM 93-95 Cobra ones. In the intrest of getting a smaller sweep across the valve tip, I'm shimming them up 0.090 and using 6.4 inch pushrods. that's two thick shims and one thin from the Crane shim kit under all the pedestals. It's kind of a compromise as to get actual proper mid-life geometry I'd have to put even more shims under to the point where the pedestal would be barely in the channel and there would be not enough bolt on the hole. Question is, think that much shim is advisable?

so with 0.090 of shims I have 0.440 bolt thread in the hole.

with that I get 20lbs of torque at 1/2 or 3/4 turn on every bolt
 

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tvsn95

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for what it's worth,,I had a new Ford racing boss long block, came with a B308 and 1.6 rollers. it had 2 thick shims as delivered.
I pulled the cam and replaced with my stock Cobra cam and 1.7 rockers.. the sweep at tip was wrong. I then noticed that the pushrods from the new long block and my original motor were Diff lengths ( shorter). long story ,but a combination of push rods and shims made it right without a ton of preload. seems like i wound up with short PR and 1 thick shim.
I know that won't answer your question but something to think about.
 
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itsell

itsell

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for what it's worth,,I had a new Ford racing boss long block, came with a B308 and 1.6 rollers. it had 2 thick shims as delivered.
I pulled the cam and replaced with my stock Cobra cam and 1.7 rockers.. the sweep at tip was wrong. I then noticed that the pushrods from the new long block and my original motor were Diff lengths ( shorter). long story ,but a combination of push rods and shims made it right without a ton of preload. seems like i wound up with short PR and 1 thick shim.
I know that won't answer your question but something to think about.
Ford racing sending out an engine with two thick shims at least gives me faith that I'm okay with the 3 Crane shims. The Ford racing thick shims are a little thicker than the Crane ones so that was likely a similar thickness to what i'm gonna run. I'm gonna roll with what i've got, put the lower intake manifold on yesterday, almost back together. Thx for the reply
 

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