Substitute harmonic balancer?

[xx88man]

Hi. The shaft of my harmonic balancer seems to have some small grooves in it. Engine is a 318 (71 with forged crank). Is there any difference between that balancer and one I have off of an older 340.
Having trouble getting a repair sleeve so just wondering if I could use this extra balancer or if they are different? TIA

[tparker]

318 and 340 use the same harmonic balancer, at least for the same year. Not sure if they changed over the years though.

One thing to keep in mind is some Harmonic balancers use an offset bolt pattern. If you get a new one, or I think later ones that don't have that, you will have issues using all the bolts for the crank pulley. Some people leave the extra bolt off while others elongate one of the holes. Just double check that it lines up.

[Chryco Psycho]

The 73 340 cast crank damper is different otherwise good to go .

[xx88man]

The one off the 340 has a little different shape on the back... curved in. Timing marks appear the same. I haven't looked at the pulley bolts yet. Thanks guys.