Oil bypass modification

[PorPete]

On my 77 3.0 I been having problems with my oil pressure since my engine rebuild. I am digging into the question; do I have the wrong pressure relief plug, spring or cap installed? I have read lots of threads about some type of oil bypass modification that can be done. Can someone tell me where this modification is done at? Does anyone have a picture to share of what the modification looks like? I couldn't tell you if my engine has been done in the past. Thank you in advance :-)

[Mo_Gearhead]

Pete,
Some additional info. may help others reply.

Did you do the engine rebuild yourself? Or who did it? What all was done during the rebuild (receipts/list of parts installed, etc.)? What oil pressure problems/symptoms are you now having?

[gottarideduc]

PorPete,

The 3.0 oil modification is needed on 2,7 and older. 3.0 are updated already.
To tell if an engine is not modified, pop the oil pressure relieve valve plug at the front bottom of the case. If the plunger above the spring has 2 holes in it, it is unmodified. If it is solid, it is the updated version.
The modification consists of milling a passage from inside the case behind the uil pump at an angle into another passage and making an aluminum plug to plug up yet another passage. That's best I can describe. Can't take pictures right now.
After the mschining the original valve plungers with holes must be replaced by solid ones or the engine will explode. Same goes for solid plungers in unmodified case.
So you are ok with your 3.0.

[PorPete]

Thanks a bunch for making that clear.

[philippeF]

pictures come from this board....