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#72160 10/20/12 08:34 PM
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who should I contat for a roller cam and lifters for a 302 Jimmy

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You could get your old cam reground, thats what I,d do as all the new ones are china


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Only person I know of that has any GMC billet roller cam blanks available is Donnie Johansen, he had a half a dozen or so on hand the last time I spoke to him. Not sure where you are going to get any roller lifters, there probably hasn't been any new ones made in over 40 years.



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Check out the 12 Port Advertisers link at the left of this page. I'm not sure who makes roller cams for GMCs.


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As i recall, Tom Langdon had a McGurk roller cam in the GMC that powered his '39 Chevrolet. One might ask him about sources for a roller cam and lifters. Tom would be someone who might engineer the lifters.

Bob Garrett has a couple of Chet Herbert roller cams, and he might have one for a GMC, but i don't know that he'd part with it.

God's Peace to you.

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how can i get in contack with donnie johnson...

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"I wonder if God created man because he was disappointed in the monkey?" Mark Twain
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 Originally Posted By: andy b
how can i get in contack with donnie johnson...


Pm sent!



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I suspect that the same tappets may be suitable to adapt to the Gen-2 stovebolt motors (235, 261).
The diameter matches; I don't know if the oil passage is at the same height.
The inter-tappet distance is probably slightly less than the GMC, normally requiring the link bar to be slightly shorter. The Crower makes this difficult since (if I read their description correctly) the bars are permanently attached. Obviously, the bar could be sawed in half, shortened, and welded back together.
The link length is always a loose fit, since it must accommodate the narrowest distance between the attachment buttons: when both the intake and exhaust tappets for 1 cylinder are both at rest (TDC compression stroke). The distance is greatest when only one tappet is at full lift, such as 110° ATDC on intake.
Therefore, the link is made with the B to B "both closed" (smallest) distance pretty close to the actual tappet centerline distance, and the B-B "one open" distance large enough to suit the highest lobe anticipated (.500"?).

Why all the math?
Because the GMC tappet may fit the 235 with no mods at all, if the max 235 lobe is sufficiently smaller than the max GMC lobe.

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I bought my rockers from Crower before I ever thought about the cam. A few years back he made 10 sets and may have more available now..

I believe Don Ferguson at Paramount Forge in Wilmington Calif can help with the cam blanks. I found one on the Land Racing site that was not ruffed in. Waiting for flow #'s to start the cam design. Because of the scarcity of these blanks and their $$$ know exactly what you want to grind on it and it will fit your needs..............Good Luck


216.158 MPH 12-Port 302 GMC on 70% 171.0 MPH 302 stock head on gasoline 7 years later
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Opps....Rollers.......


216.158 MPH 12-Port 302 GMC on 70% 171.0 MPH 302 stock head on gasoline 7 years later
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i got in touch with donnie,thanks much...new phone # for donnie -909-815-9185


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