Swapping my 3.9 for a 4.2- Now no Oil Pressure

[kjj0506]

Does anyone know what's going on ?

I swapped the front cover , new gasket , new Timing set , oil pressure was good in the running donor rig and good on the 3.9 , I did not remove the pan to check the pick up because it was ok in the donor , I can spin the pump  with an air tool and get it to flow.... but when I have the distributor in there is no flow.

Attempted the vaseline trick to prime too... nothing.

Should I get a relief valve and seal set for the pump ?

[kjj0506]

I pulled the front cover back off and used the gasket for the 3.9.... it worked. The one for the 4.2 was obscuring an oil passage just a smidge so...

Hope this folly of mine helps some one some where