how can i tell if my oil pump is ok?
engine seems to run very hot

new rad water pump engine fully rebuilt just didnt fit a new oil pump

bit silly i know

when engine running and oil filler cap off seems there a bit of pressure blowin out
is this normal

cheers

 

With a new engines till the rings are bedded in there will be more blow by than normal as they won't be sealing as well as used engine.
If the oil pump was ok then there is no need to change it, did you inspect it ?
If the oil pump was causing excess temps due to not enough oil supply, the temps would be the least of your problems, you'd know by now for sure, maybe new engine paranoia!!
tabetha