Break In Disaster????????

Some more info please: What weight of oil? And how warm is warm? What RPM's? What oil pump; standard or high volume or high pressure?

Did you put in a Melling oil pump? Per KrazyKuda, they use a 72 psi relief spring. We primed our 340 last week, with 10W30 oil and a Melling HV oil pump with the heavier spring in it (presumably the 72 psi spring). At 600 rpm on the pump (equivalent to 1200 crank RPM), it produced 67 psi with room temp 10W30 oil on a 60's Stewart Warner gauge.

Dunno any other way to test the actual pressure than a gauge. Run up your RPM's and if it does not gain more pressure, then that is likely where your relief spring is set. If it keeps going up with RPM in the to 80+ psi range or higher, then it is time to think about a relief spring issue.... or a bad gauge.

And good deal on the rocker shaft bolt!