Oil + additive viscosity
I think I've seen a photo of that oil filter set up on a UK - RHD v-8.
I don't think the ID after the pump is causing the issue. Someone here will know the ID of the oil passages in the block.
But on US models, the pressure gage is also after the pump and filter.
Interesting it has a check valve in the center of the filter bracket. Does it look like one of these?
IIRC, the one with the coarse threads was used here on slant 6s - at least some, another is from a Chrysler marine engine - it has a check valve. The third, don't recall. I'd have to dig up my notes. I've used the check valve when I was using an accusmp. It does look restrictive but apparently not enough to make a difference like your describing.
I think I've seen a photo of that oil filter set up on a UK - RHD v-8.
I don't think the ID after the pump is causing the issue. Someone here will know the ID of the oil passages in the block.
But on US models, the pressure gage is also after the pump and filter.
Interesting it has a check valve in the center of the filter bracket. Does it look like one of these?
IIRC, the one with the coarse threads was used here on slant 6s - at least some, another is from a Chrysler marine engine - it has a check valve. The third, don't recall. I'd have to dig up my notes. I've used the check valve when I was using an accusmp. It does look restrictive but apparently not enough to make a difference like your describing.