H hootsk New member Joined Jul 2, 2015 Messages 9 Reaction score 0 Points 0 Jul 27, 2015 #1 My '87 GMC Suburban has a TBI 350. Should I be adding ZDDP at oil changes? How can I tell whether it needs it? Chuck Seattle
My '87 GMC Suburban has a TBI 350. Should I be adding ZDDP at oil changes? How can I tell whether it needs it? Chuck Seattle
zora Staff member Joined Apr 24, 2012 Messages 5,518 Reaction score 139 Points 63 Jul 27, 2015 #2 everything I see says trucks did not get roller cams till 1996, so you should be adding some type of additive since you have a flat tappet cam.
everything I see says trucks did not get roller cams till 1996, so you should be adding some type of additive since you have a flat tappet cam.
H hootsk New member Joined Jul 2, 2015 Messages 9 Reaction score 0 Points 0 Jul 27, 2015 #3 Thanks, zora
