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  1. #1
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    Default Cam swap done..... pushrods not even close

    Just got done swapping in a custom lunati cam from. Member here and with my 1.6 rrs they seem to be almost 1/2" to short, is that even possible to be that far off? Not sure what size the base circle of the cam is but obviously smaller.
    In fact after installing the pushrod guide plates when I sit the rocker down over the stud the rocker body will just bottom out on the flange of the stud with about 1/4" of slack left in the pushrod.
    Just wondering what everyone else measured out to, now I need to buy a length checker and new pushrods.........

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    Quote Originally Posted by fullforce View Post
    Just got done swapping in a custom lunati cam from. Member here and with my 1.6 rrs they seem to be almost 1/2" to short, is that even possible to be that far off? Not sure what size the base circle of the cam is but obviously smaller.
    In fact after installing the pushrod guide plates when I sit the rocker down over the stud the rocker body will just bottom out on the flange of the stud with about 1/4" of slack left in the pushrod.
    Just wondering what everyone else measured out to, now I need to buy a length checker and new pushrods.........
    Entire valve train geometry is different, so yes that's normal. Prolly need a 7.3. I run 7.150 with sa rockers.

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  4. #3
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    Default

    By a checker, measure out to final length. Don't even question doing anything else.

    Also if you reused the lifters make sure they're not collapsing. Ran into that on a buddies car. $780 set of Lunati Tie Bar lifters had taken a shit.
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    Checker is on the way...... I'll report back with my findings.
    I am reusing the lifters... I hate being broke

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    Quote Originally Posted by fullforce View Post
    In fact after installing the pushrod guide plates ........
    did you use rocker studs for guide plates????

    they have a recess to absorb the extra height of the guide plate.

    is the Lunati cam base circle smaller than OEM cam?

    1/2" is insane amount of difference in PR length....something is way off or measurement procedure is

    what is installed height of springs?

    PR length checker is needed to measure PR length...one simple one to use is (pic) by Proform for about $10 they make 3/8 & 7/16 size
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    Default

    I used longer studs, I didn't know they made them recessed though.
    The tip of the rocker is contracting the very outside of the valve stem.

  9. #7

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    It sounds to me Like the guide plates and studs are incorrect for the application. can you post a pic of the rocker on the stud and the gap on the pushrod. If the stud shoulder is holding the rocker too high to center on the valve then either the heads arent machined for guideplates or the studs are incorrect. A pic would clarify a lot.

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    Quote Originally Posted by superspirit View Post
    It sounds to me Like the guide plates and studs are incorrect for the application. can you post a pic of the rocker on the stud and the gap on the pushrod. If the stud shoulder is holding the rocker too high to center on the valve then either the heads arent machined for guideplates or the studs are incorrect. A pic would clarify a lot.
    Quote Originally Posted by BALLSS View Post
    did you use rocker studs for guide plates????

    they have a recess to absorb the extra height of the guide plate.

    is the Lunati cam base circle smaller than OEM cam?

    1/2" is insane amount of difference in PR length....something is way off or measurement procedure is

    what is installed height of springs?

    PR length checker is needed to measure PR length...one simple one to use is (pic) by Proform for about $10 they make 3/8 & 7/16 size
    If they are arp studs, they are ALL manufactured for guideplates, and are not recessed, not sure what is meant by that.

    The proform tool is great, I have one and just used it and it worked perfectly and quickly.

    Just wait till ur length checker shows up, until then, if it comes out to like a 7.8" then be concerned, if not, just calm down and get it right

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    The wrench/driver for LTConvert's 94 Z28- Ellwein 383/LE Trickflows/ D1SC / CPT Ultra Pro Race 4L60E
    10.78 @ 125mph. Shooting for 9.99 for Frank Cahall!

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    Quote Originally Posted by Tubby Z28 View Post
    If they are arp studs, they are ALL manufactured for guideplates, and are not recessed, not sure what is meant by that.
    You can use them all with guideplates, but not all of their studs have the locater shank. ARP's site specifically lists which ones have it. I agree with the latter, not sure what was meant by the previous post.
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    Default

    Yes ARP makes studs for guide plates with the locator recess.

    Sounds like the OP is using longer studs which is raising the rocker to high.....or he is putting the RR fulcrum on the stud upside down. The flat part of the fulcrum goes up.
    96 BBB 383/T56

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