Acquired Toyota engine gasket kit for 1999 LS400
containing 32 valve stem seals: should be 16 intake and 16 exhaust.
Not labeled with part numbers , so am unable to ascertain which is which.

One set had a red tag while the other 16 did not.

Anyone know how to differentiate?

Thanks.

 

i'm sure there is a physical difference, perhaps not dimensionally but visually in that the exhaust seals are likely treated differently with a coating or the like.
of course this still leaves a 50/50 guess as to what goes where.

what I would do is go to a dealership (Toyota/Lexus) or local mechanic shop and see if they can distinguish the parts.

 

I expect the hole diameters will let you know - match the seal hole diameters with valve stem diameters.

The intake valves will be bigger than the exhaust ones, and the stems may match in size.

Nice pioneering work here.

 

Am going to let Toyota sort this out.

Parts with similar physical appearance, but different composition should be labeled.

The machinist commented the original seals were hard, so it was time to replace them.