1962 305 V6 oil filter sizing issue
 

Hello everyone! I searched through the forum and across the internet and couldn't seem to find any information on my issue.
I just bought a Franken-truck that has a cab, that according to the VIN, is a 1960 or 1961 GMC K1000 series, although it doesn't have the eyebrow hood. It has a hood from the next body style that is flat across the front. The chassis and drivetrain seem to be from a 1962 model 3/4 or 1 ton 4x4. Its a dually. Dana 60 rear, dana closed knuckle 44 front, SM 420 4 speed, unknown twin stick transfer case. Motor is a 305v6 with a Stromberg WW and the intake has a 1962 date code.

The issue I'm having is I'm going through all the fluids and when I dropped the oil filter canister, the filter that was in there is smaller than the replacement P122 that is listed as the correct filter. The new P122 measures about 3 3/4” in diameter and the old filter about 3 3/8". They are both about 5 15/16” tall. If I use the P122, it physically fits in the housing, but there is only about an 1/8" to 3/16" space between the filter and the housing where the other had quite a bit more room, and I'm assuming better flow through and around the filter. I can't find any mention or part numbers or anything about this smaller filter. Anyone have any idea? Smallest one I could find linked to a GMC of this era was on Rock Auto and was still a smidge over 3.5". Help!

Re: 1962 305 V6 oil filter sizing issue
 

I crossed over the P122 to a NAPA (Wix) 1121, which appears to be the right oil filter for a 1963 305. O.D. of the 1121 is 3.778", I.D. is 1.095", height is 6.339". NAPA says a 1960-1962 305 V-6 should take an 1123, which has an O.D. of 3.594", I.D. is 1.281", and height is 6.37". I hear what you are saying about the O.D. of the filter element and the I.D. of the can being so close, it could cause a flow problem. Have you tried the 1123 or equivalent? Sounds like it would be a better fit.

Re: 1962 305 V6 oil filter sizing issue
 

Bob thanks for the reply! I am definitely going to try an 1123 next time and see if that works better. I'm a little concerned that it may be a little too tall though. For now I just popped the P122 in it so I could get it filled back up and moved out of the driveway to make way for pouring my garage slab. There was so much sludge in the pan and the filter canister that I am probably going to change the oil again very soon.