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Discussion Starter · #1 ·
i have a 521 that is going together and when i went to put the pushrods in they are binding with the guide plates. they are hitting not so much on the sides but in the middle portion in the back of the guide plate. I am runnning comp cams guide plates with dove heads 3/8 pushrods hi tec comp cams. i was out of answer on this one so i had a set of comp cams 8.550 5/16 push rods ans manley guide plates so i switched them to see what they would do because they were on the old 429 that i built with the same heads and they fit fine. well i was thinking with this new motor that i should go 3/8 because i am running a roller cam with .680 lift and about 625# open pressure i thought all i would have to do is change the guide plates and pushrods and it would be fine. I am also running scorpian 1.73 roller rockers . any thoughts would be greatly appreciated
 

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Are the guide plates on upside down? Is the roller contacing the valve tip in the correct location through the full travel? Are all the pushrods doing this or just a couple? Perhaps they are the wrong guideplates:eek:
 

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Discussion Starter · #3 ·
they are the right pushrods i measuresd them with a pushrod length checker and i an experianced with measuring pushrods. there is no way to install them upside down because they are raised on one side and it seems to be both intake and exaust but it looks like more the exaust giving me trouble
 

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Discussion Starter · #5 ·
they are scorpain 1.73 bbford rocker arms brand new an i tried my old comp cam pro magnumn rockers with the same problem
 

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Check the part number on the guideplates. If the number is correct call comp and see what they say. I wasn't trying to insult you by asking if they were upside down just don't know your skill level so hope you weren't offended.;)
 

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loosen thhe studs and see if the plate will move in little,if not maybe take the hi-speed grinder to the slots then polish them with some 400 grit paper wrapped around a pushrod?
 

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Have the heads been machined for guideplates ...?
Going to 3/8" pushrods will often do this if the heads are left unmachined at the stud bosses.
 
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