More Magnum Block Oiling Questions

75slant6 said
So do the later blocks without the oil holes NOT have those 1/2” cast tunnels in the valley? I’ve never taken the heads off my 5.9 to see if the oil holes are there, but it appears to have the cast tunnels (pic from several years ago). Speedmaster STILL doesn’t have their stainless rockers (oil through pushrod style) in stock. Could buy prw’s but they’re twice the price. If the oil holes are there, I can buy any LA rockers.

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Regardless of the rockers you go with I'd highly recommend hitting up @B3RE B3 Racing Engines to get a valvetrain geometry correction kit, especially if you are using a roller cam. He sells PRW rockers btw. You will also likely need to clearance the pushrod holes in the heads a decent amount if using a roller cam combined with aftermarket rockers because the pushrod angle is different than with flat tappets.