Brand of engine (GMC or Chevrolet)?

Size of engine?

Year of engine?

Optional 216/235/261 by-pass oil filter Tech-Tip - if you have a GMC, the plumbing (at least) will be different.

High-pressure 235/261 full-flow conversion (does this work on a low-pressure 216/235??) - if you have a GMC, the technique might be different?

If you have a GMC 228/248/270/302, information on the full-flow upgrade can be found at oldGMCtrucks.com