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#1
09-15-2019, 04:15 PM
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3/8 pushrods
Is it worth stepping up to a 3/8 pushrod on a roller cam/valvetrain? What is all necessary to make them fit and clear without issues? Will be going in the 432 with edelbrock round port heads I’m in the process of building. I was looking at the Smith Bros 3/8x.120 pushrods from Butler.
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1967 GTO, 432 (428+.030), 4-bolt mains, factory Nodular crank, scat rods, icon dished pistons, Lunati HR 243/251@.050, .618/.622 lift, Edelbrock 72cc round port heads, 10.5:1, offy 2-4 intake, Edelbrock 650cfm carbs, Super T10 trans (2.64 first), BOP 10 bolt w/ Eaton posi and 3.36 gears |
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#2
09-15-2019, 05:11 PM
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hyd or solid?Tom
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#3
09-15-2019, 05:14 PM
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Quote:
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1967 GTO, 432 (428+.030), 4-bolt mains, factory Nodular crank, scat rods, icon dished pistons, Lunati HR 243/251@.050, .618/.622 lift, Edelbrock 72cc round port heads, 10.5:1, offy 2-4 intake, Edelbrock 650cfm carbs, Super T10 trans (2.64 first), BOP 10 bolt w/ Eaton posi and 3.36 gears |
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#4
09-15-2019, 05:29 PM
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Doubt you will need them.I have a engine going together right now with 160 on the seats and we are using 11/32 because that is what the guide plates are.I have used heavy wall 5/16 Smith Brothers with 200 on seats before with no issue.FWIW,Tom
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#5
09-15-2019, 09:47 PM
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I’d still be curious as to what would be necessary to run them. While I doubt they’d be necessary it doesn’t sound like it’d be a bad upgrade to prevent any pushrod deflection.
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1967 GTO, 432 (428+.030), 4-bolt mains, factory Nodular crank, scat rods, icon dished pistons, Lunati HR 243/251@.050, .618/.622 lift, Edelbrock 72cc round port heads, 10.5:1, offy 2-4 intake, Edelbrock 650cfm carbs, Super T10 trans (2.64 first), BOP 10 bolt w/ Eaton posi and 3.36 gears |
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#6
09-15-2019, 10:04 PM
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Depends what heads and rocker the actions and guide plates.Tom
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#7
09-15-2019, 10:05 PM
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Rocker ratio!
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#8
09-15-2019, 10:06 PM
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Edelbrock round port heads and Harland sharp 1.65 full roller rocker arms.
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1967 GTO, 432 (428+.030), 4-bolt mains, factory Nodular crank, scat rods, icon dished pistons, Lunati HR 243/251@.050, .618/.622 lift, Edelbrock 72cc round port heads, 10.5:1, offy 2-4 intake, Edelbrock 650cfm carbs, Super T10 trans (2.64 first), BOP 10 bolt w/ Eaton posi and 3.36 gears |
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#9
09-15-2019, 11:42 PM
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IMO, you're throwing extra weight into the valve train for nothing (so far as I have read) that 5/16 .116 wall size Smith Brothers pushrods couldn't easily handle.
What size is the cam and are you bracing the lifter valley too?
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Only a pawn in game of life. 
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#10
09-16-2019, 06:58 AM
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Quote:
__________________
1967 GTO, 432 (428+.030), 4-bolt mains, factory Nodular crank, scat rods, icon dished pistons, Lunati HR 243/251@.050, .618/.622 lift, Edelbrock 72cc round port heads, 10.5:1, offy 2-4 intake, Edelbrock 650cfm carbs, Super T10 trans (2.64 first), BOP 10 bolt w/ Eaton posi and 3.36 gears |
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#11
09-16-2019, 10:05 AM
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You also dont need the lifter brace with that small of cam.Tom
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#12
09-16-2019, 10:13 AM
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Quote:
__________________
1967 GTO, 432 (428+.030), 4-bolt mains, factory Nodular crank, scat rods, icon dished pistons, Lunati HR 243/251@.050, .618/.622 lift, Edelbrock 72cc round port heads, 10.5:1, offy 2-4 intake, Edelbrock 650cfm carbs, Super T10 trans (2.64 first), BOP 10 bolt w/ Eaton posi and 3.36 gears |
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#13
09-16-2019, 12:44 PM
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No need for 3/8" pushrods for a HR cam. You would have to find or make or modify some guide plates to do it. They would need a 5/16" balls and undercut rocker tip end. Also probably need to grind more clearance into heads.
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Paul Carter Carter Cryogenics www.cartercryo.com 520-409-7236 Koerner Racing Engines You killed it, We build it! 520-294-5758 64 GTO, under re-construction, 412 CID, also under construction. 87 S-10 Pickup, 321,000 miles 99Monte Carlo, 293,000 miles 86 Bronco, 218,000 miles |
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