355 Motor Mounts

I'm looking at replacing the motor mounts this winter on my 355 and would like to go to the heavier duty Challenge mounts. However, it looks like they aren't carried at the usual places but cross reference to a 550 motor mount (which has been superceded with a newer mount cross compatible with the 575). Can anyone confirm that the newer 550/575 mount will fit in the 355, or anybody have both that they can look at? Thanks.

 

pm me if you want em.

 

Bump. I am in the same boat as the OP was and would like to know if 575 mounts will work with the flat plane crank F129B engine.
575 engine mounts are the updated unit for the early 456 mount which cross-references as the F355 Challenge mount.

Thanks.

 

What's the difference, just harder rubber?

 

What do you hope to achieve by getting "Heavier duty motor mounts"?

355 mounts last a long time. Longevity isn't an issue.

 

Mine were toast at 42k miles, I think I ended up finding the challenge mounts somewhere, which were similar material but had more of it iirc. I'll have to look through my records to see which I bought and where I got them.

 

They get killed by heat. Super easy to shield them.

 

@bobzdar
Thanks for chiming in.

Regular 360 mounts look very similar to the 575 mounts as they both feature a cross plate at the top. I do not see why anyone would want to keep using either standard or Challenge F355 mounts when either the 360 or 575 mounts seem stronger as more recent designs... unless the bottom rubber shims used on the F355 must be kept - has anyone successfully used either 360 or 575 mounts without these F355-specific shims?

 

To answer my own question, I fitted 575 engine mounts and F355 Challenge transmission mounts on my F355 and they work great.
I could not say if there are any more vibrations at idle than there would be with new stock F355 mounts but there are far less than with shot stock mounts.

 

I replaced mine at 60K (and 5K track miles) with challenge parts.

I noticed no change in vibrations or noise.

 

Good to know.