New to big trucks with my 1968 peterbilt 359

oe was a bag that looked like a sock when pulled out. If it has had the conversion kit installed this will be the replacement. Baldwin makes one too.

 

That really does point toward 4:88’s. Thats why you are gear bound in the 62-70 mph range. Even with the od in the aux. thats all you will have.

 

The only other two filter options it could have in that vintage would be this one. These were used on the NTA420’s only and would make it a very rare bird or this big canister mounted somewhere on the left side with #16 external lines. But this style was NH743 mostly. 855’s should not have used it. But crazy things happen.

 

It has the oil cooler on it. The only 855’s that I can think of with those style coolers that did not have filters on them would have been the NTA’s. Does it have an after cooler or just intake manifold straight to turbo?

 

Looks like you have a NTC335. They had the old style round water pump with the new FFC oil cooler, piston coolers, no after cooler, the oil filter is in the up right canister on the front of the cooler.

 

Anything is possible after that many years. Things get mixed up in time. Some vocational trucks had odd horse power settings. Autocar roll off trucks here had that filter set up but they were not 335's. Do not remember what they were but the trucks were made about 1980 - 82? They were replaced by 1987 and 89 Autocars with 270 Big Cams. Does not sound like much but they were strong pullers under load.