Ok so I blocked the outside hole but couldn't get the center one out before it was time to head to the lake. I couldn't get a bolt to work on either bypass so I just popped the outside one out with a screwdriver but the center one is too deep for that. Taking just the one out helped my oil pressure problem out quite a bit, but not enough so I need to get center bypass out. Does anyone have any ideas for getting that one out? I tried different size bolts and lag bolts but nothing would grab a hold. I did not try metric however

I used a starter bolt and tapped it in with a hammer.

Just went through all this stuff, pulled out the valves, changed to a remote filter pad that blocks the relief hole in the pad. Did new thermostatic oil coolers with all -12 lines and fittings. Oil pressure now stays 60psi at idle and 80psi at speed regardless of temp, which with the new coolers does not go over 220. Definitely a big difference.

Never mind - did not see that you blocked the outside bypass. Center bypass just routes the oil through some extra passages for the external cooler. May or may not help your pressure to remove this.

feel like putting together a walk through for us non mechanical types?

Out of curiosity, what was your oil pressure before these modifications?

Bump as this seems relevant here lately.

Just clarifying the oil route so I don't get anything crossed up. The oil leaves the block adaptor from the offset nipple, to the remote oil filter, to the oil cooler, and then back to the center port on the block adaptor, correct?

Yes.

I currently have been using a moroso sandwich filter block adapter on a Merlin block however the outer o ring lands just barely on the edge of the block filter pad as this block pad is smaller than the ones on the GM blocks. I am concerned about it leaking a little there. I like the simple pluming with this setup and can just reach the filter to change it. Does anyone make a sandwich adapter with the double o ring seal for the Merlin blocks or do I need to either fabricate a special gasket for the adapter to block seal or go to the double o ring block adapter and set up a remote filter?

If it has two bolts that hold the block adapter to the filter pad (Mark iv) I have everything you need to mount the filter off the back of the port head with lines. Pm me if interested. If not interested in what I have everyone and there brother makes block adapters that will work.