EProdRx7

How can I determin if the counter weights, front and rear, are from an 89-91?

spunks

Part numbers.

EProdRx7

No realy? problem is, that I have a bunch of them without part#'s on them smart ***. I'm looking for visual clues...

FxF

Aren't they the same?
Did you do a search?

spunks

s4 and s5 counterweights are different.My s4 counter weight has only one hole drilled into it.Weigh them and see if they have a different weight to them.Because they all look alike visually.

rotarygod

iTrader: (1)

The counterweights are visually identical. The holes drilled in them mean nothing in terms of determining which years they are. The '89-'91 counterweights are lighter than all the earlier ones but only very slightly. It would take a postal scale to see the difference. I had this scenario several years ago with 2 different counterweights during a rebuild. I flipped a coin and hoped the engine wouldn't shake when started up. I got lucky. Unfortunately I don't really have anything helpful to tell you.