if you ensured all air has been purged from line then you should be fine. 20-60 psi is normal. inline engines have a pressure build up different then typical v6 setups and part by design with spikes. i would switch to 5w30 for sure. but also consider age of your rings as well and if get bored, pull your pan and check the journal's on your crank. otherwise run it till she don't run no more enjoy.