I think that's why these work so well....they're not a "through bolt" design". And from what I've been able to compare to, a slightly softer durometer.

 

i have installed that type as well, the cons were they put the engine up almost an inch higher than stock so it may interfere with strut braces and the brackets can be a pain to fit into the subframe channels. aside from those 2 things they are nice mounts.

 

For what it's worth, I would 100% buy the diff brace if it were legal is the ASP class. However since it's not, I need to make due with what I can.

Would poly engine bushings make much difference in fore-aft movement of the engine? Or predominantly side to side?
Thinking about how it's set up, it seems like the diff bushings would make a bigger contribution to minimizing the fore-aft movement (and reducing fore-aft shifter movement on loading/unloading the engine)

 

Almost an inch? Mmmm, not what I remember. My engine sits higher, about 1/4" higher. But it's due to that pan brace you see in the picture and my stupidity/failure to have the arms milled 3/16"....not the mounts.
I'd kept hearing they were taller too and "eye-balled" them against my OEM mounts but saw little difference. I wished I'd measured or at least taken a picture. And I had no problem clocking them to fit in the subframe wells.
But whatever, practically speaking they're not an option for most because they're hard to find here. They are an example of the non-through-bolt design and I'm happy with them.

Generally speaking mounts have come along way in my memory. I remember guys using hockey pucks and just turning hunks of solid aluminum on a lathe. I also remember a ride in an FD with a set of the old Gotham Racing mounts which were pretty harsh. Now different durometers and varying designs. Definitely a good thing.

 

IMO you're over thinking this. At IRP almost every car that's getting an engine leaves with the shop poly mounts. There is no vibration on stock cars with the soft durometer, they outlive the stock ones, are less prone to falling apart, cost less, and make the engine much easier to drop onto the subframe.

I can't find one redeeming quality for the stock mounts.

 

The only positive with running the stock mounts is that they're already installed

I was content to go ahead with the install until I saw that I had an aluminum mount. Now I'm questioning whether it's worth jumping into the more involved process while I'm using a garage with no lift

 

the stock mounts do have straps, for when they do eventually fail and to avoid over stressing the mounts. i suppose i am in the minority and think the stock mounts really aren't that bad.. they just do not mix with oil and tend to fall apart after about 7 years or so.