just rebuilt runs bad

If it's got the "10:1 pistons and RHS heads" with a small cam, I think 145psi is low. If it was me, I'd talk to the machine shop to see if it's ok for you to pull the intake to inspect the cam. 1500rpm is not really high enough to splash enough oil up to the cam, which is why the rpm is high when you break in the cam. I use 1800-2000 rpm. Otherwise there's not enough oil pressure to cause a lot of splash off the crank and rods... I'd check the cam visually before any more running or turning over. if the shop does not want you to, they should send someone over to do it.