Any way you slice it. There is no fourth hole. Even my Moroso mounts are the same way.

 

The same mount was used in different vehicles. Perhaps it's a lack of accessibility in the Camaro frame leaving the 4th hole unused?

 

You are correct Chuck. If my brain is still working right. The sub frame folds over to create the side right where the fourth hole would be. I would guess if I tried them in my pickup things would be different. If you ever look at a second gen sub without any mounts, there are sooo many holes it hurts to look at. If you look back at the two bodies (Camaro/Firebird) and the different engines available it blows your mind. I have personally seen Camaros with I6's V6's SBC and BBC. Pontiacs with SBC, and Olds 403's as well as the Pontiac blocks 350-455 all being the same. There are six or so combos right there. never seen a I6 in a Bird but I wouldn't doubt it. I'm sure there is hard evidence of all the combos out there, I'm just stating what I have seen.

All that being said, I couldn't get four holes to line up for a SBC. LOL

 

I can just picture the designers at GM when they wanted to make the mounts work using all 4 bolt holes. Ehhhh....3 is plenty, yeah that's it!! Now we save the cost of 2 bolts on every car we make.

 

Thanks guys for your feedback. Shall I drill the frame to match the 4th hole?? Or there is no such need.

 

While I do find your comment humorous. I know your getting at the recall. I cant say I feel responsible or anything more than just bad. But I cast the housings for the ignitions. The spring for the detent they blamed for all this rode on the casting. This particular casting was without a doubt one of thee worst tools I have ever come across. Like I said, just feel bad about knowing that I shoved these out the door fast as we could make them and people died.

 

I think the frame mount with 4 holes was a later 2nd gen Camaro thing, after they went to clam shell type motor mounts. The earlier 2nd gens didn't have that 4th hole:

 

Then there are the dreaded "performance mounts" the discount stores sell. They fit exactly nothing.

 

Went through that with my '71 and the local performance parts store. I tried every Energy Systems poly mount they had, and none of them fit the 427 in my car! I finally had them bring in several Moroso solid steel mounts and found one set that fit perfectly. Some people don't like solid steel motor mounts, but I have them on my Falcon and the Austin also, and on a car with much HP I think they're the best choice. Vibration transfer is really not that noticeable vs. poly mounts.

 

Eh, I had solid steel mounts on mine and changed to poly. I did notice a little bit of a difference in less vibes. The poly mounts won't separate like standard mounts since they have an interlock molded internally. One good thing about solid mounts though, is that it makes your engine part of the frame.