What are the main differences between the wix 51061 and 51036 filters?
What pressure differences would there be?
the main differences I see are the flow rate, size and threads.

the 51061 has
Style: Spin-On Lube Filter
Service: Lube
Type: Full Flow
Media: Paper
Height: 5.178
Outer Diameter Top: 3.66
Outer Diameter Bottom: Closed:
Thread Size: 13/16-16
By-Pass Valve Setting-PSI: None
Beta Ratio: 2/20=6/20
Burst Pressure-PSI: 285
Max Flow Rate: 9-11 GPM
Nominal Micron Rating: 21

the 51036 has
Style: Spin-On Lube Filter
Service: Lube
Type: Full Flow
Media: Paper
Height: 4.828
Outer Diameter Top: 2.921
Outer Diameter Bottom: Closed:
Thread Size: 18X1.5 MM
By-Pass Valve Setting-PSI: None
Anti-Drain Back Valve: Yes
Beta Ratio: 2/20=6/20
Burst Pressure-PSI: 325
Max Flow Rate: 7-9 GPM
Nominal Micron Rating: 21

I know the factory oil filter for the lt1 c4 is a 51036 but I am using the 51061 and am curious on the differences.

EDIT
or should i be using a 51060?
Style: Spin-On Lube Filter
Service: Lube
Type: Full Flow
Media: Paper
Height: 5.178
Outer Diameter Top: 3.66
Outer Diameter Bottom: Closed:
Thread Size: 13/16-16
By-Pass Valve Setting-PSI: None
Anti-Drain Back Valve: Yes
Beta Ratio: 2/20=6/20
Burst Pressure-PSI: 270
Max Flow Rate: 9-11 GPM
Nominal Micron Rating: 21

 

I'm just a tad confused. The major differences among the three filters are that the 51060 and 51061 have SAE threads while the 51036 has metric threads. Which engine are you planning to use one of these oil filters on?

 

LT1
50136 is with factory adapter
51060 and 51061 is with a old SBC adapter.

Don't forgot the size and flow differences.
51060 & 51061
Height: 5.178
Outer Diameter Top: 3.66
Max Flow Rate: 9-11 GPM
51036
Height: 4.828
Outer Diameter Top: 2.921
Max Flow Rate: 7-9 GPM

and the fact that the 51061 doe not have an Anti-Drain Back Valve but the 51060 and 51036 do.

EDIT
also don't forget that you can get a 2 quart version of the 51061

 

I wouldn't use an oil filter that didn't have an anti-drain back valve on my engine. Most of real engine wear occurs during the start-up process when the oil pump is trying to get the oil to flow to all parts of the engine. Having to replace the oil that's drained back into the sump just exacerbates that process in my opinion.

I prefer as large an oil filter that will fit w/o interference with my headers nor extends below the oil pan. Therefore I would choose the 51060 out of the two remaining filters.

If you're running a heavier oil than the factory recommended fill of 5W-30, then the 51036 with a lower flow rate, but a higher burst pressure might be a better choice.

Just my thoughts on the matter. Hope this helps.

 

I normally run 10W-30 and sometimes 5W-30.
Before I got thinking about this seriously I found it interesting that changing from the 51036 to the 51061 (might be 51060 need to change it and will look then) dropped the oil pressure about 25psi across the board.
I am guessing the increased flow rate did that?

By pressure drops I mean this
with the 51036 I got about @ idle
75psi cold
50psi warm

with the 51061 I get about @ idle
50psi cold
25psi warm

 

Oil pressure is generally measured AFTER the filter. Make sense, you want
to measure the oil pressure getting to the bearings. If I changed filters
and the oil pressure went down, I'd change filters again ASAP as there's a
restriction in the filter.

 

Not sure about a restriction in the filter. It seems to me that f-body lt1s have about the same oil pressures I do now and they use a 51069 for a oil filter. The 51069 is a weaker version of the 51061. The only thing I can see that might cause it is that the between 51036 (lt1 vette) and 51069 (lt1 camaro) the 51069 has a constant 2gpm higher flow rate.
IF I understand that principle correctly it means the 51036 was the restriction.