Top end oil restriction

I'm putting in a new cam need to go faster. My old comp cam did not have the curve around the #4 cam bearing. The new one has, does anyone know how much restriction I should put in.

Never had a problem before on the shut down at the top end. Thanks

I've used .120,.080, .060 in the stock oil galleys to the heads using ductile iron rockers and .039 in my Indy headed motors with Harland Sharp and T&D roller rockers and a grooved # 4 cam journal I help a local racer with a set of Indy 440-1 that fought the same problems on his motor on the dyno, loosing oil pressure do to insuffeceint oil return so I started my Indy headed motors at .039 in the pressure lines to the heads What type rockers are you using now? The World iron blocks have a .040 restritor in there oil galleys to the heads

T&D rockers Thanks for the good advice. So you just put the .039 in the heads and not the block it really should'nt matter were it's at. With the heads off should be easy.

I've drilled the blocks so a Holley jet wil fit and I've done the same thing to the heads, your choice The Indy heads have seperate oil lines from the back of the block oil galley passages to each head, not sure if you knew about that. My message is the blocks I have restricted had grooved cam journals, .030 wide and close to .030 deep, not the same flow capicitys as the external oil lines like the Indy heads use I would, and have, use a .060 in the block first, way better to have a little to much oil feeding than not quite enough

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T&D rockers Thanks for the good advice. So you just put the .039 in the heads and not the block it really should'nt matter were it's at. With the heads off should be easy.

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With T&D rockers just use regular hold down bolts, not the under cut studs, and that will restrict oil flow to the rockers

Just joking, I've been fighting rocker issues for the last few months, and today the Heli-coil insert pulled out of the head (I think the rocker arm bolt was too short?)