My first suspicion with a big block, HR, and high RR is always lifter issues.
Similar cube combo, 505 BBM, mid-10’s CR, ez-295’s, Indy 2-D, HS 1.6 rockers, HR………. 640/640.o
Yeah I agree. I suspect the lifters are just starting to complain at 5800 rpm. It hits earlier in a BBF due to the 1.73 rocker ratio. We made a few pulls today for the customer and it ran better today than yesterday. Probably due to rings seating after a few heat cycles. Peaks were up to 660 torque and 650 hp so it will be a stout truck motor. Going in a F250 4 wheel drive dually pickup.
The Sniper duty cycle peaks at 88% so it isn't running out of fuel. It is pulling about 800 cfm according to the turbine so it is close to running out of air. The manifold vacuum at WOT bounces around between 0 and 1.5 inches so there is some restriction but not a ton.
