I thought the same thing, but I have seen people safely run a 3800 in an originally 3400 powered w-body chassis with the 3 both design. I have also seen in the Grand Prix forum someone running the same aluminum mounts Frank is playing with (I believe on a super charged 3800). I don't think they trimmed there mounts. I'm fairly certain this swap ranks as "worth a try". Worst that should happen is the aluminum mount cracks due to the way the engine pushes on it with only 2 bolts holding it in, and it will probably drive/feel goofy until the original mounts are put on. But I'm far from an expert on this

Yeah, no matter what you're going to come out on top (heck even with those rad mounts, you spent less then the ZZP pricing). BTW - Can you notice a weight difference in the two different rad mounts?

At one point I was considering switching my rad and dog bone mounts for the mounts I think the early 90's wbodies had. They had round solid rubber bushings on both dog bones, in theory it should be a similar effect I will have with my "poly mount" swap (which I think is really rubber to begin with, but now I have solid rad mounts). Plus those older dog bones are aluminum and they could be polished to look nice. I dropped the idea (but still think about it once in a while).

We'll see :rolleyes: lol

Good to hear Brock ;)
I think I should be fine with 2 of the bolts, I say that because the engine is mostly rocking back and forth and not down and up. If that were the case then yes that would most certainly be a bad idea lol :p

Thanks man :)
Haha yea you could've Lou, but who was to know about them? :p I sure didn't lol


Well wish me luck with them :)
And yes there is a noticeable difference in weight With these being aluminum. Also I forgot to mention, are all 04 and up GP's 3800's? Because I could've swore I seen one of em with the mounts still on and it had the same design as these aluminum ones I have. I'm not 100% on it though, maybe I'll go down today and take a look :confused:
But before i do any more sanding or buffing Im going to install them and drive my monte with them just to see how it runs with the 2 bolt setup. I'll try to find them dogbones you're talking about too ;)
What kind of cars would I find them in?

Frank they all had the 3800, 3800 supercharged, or the LS4.

Jessica has one with a 3800 and I thought the engine mounts were the same or pretty similar but I could be wrong.

I just looked and they are the same, I can't post this pic because it's huge but look here:

http://static.cargurus.com/images/si...pic-40523.jpeg

oh ok thanks mitch, they are the same as 3800 montes then :p

ok guys so i ran into a small issue. :o

these alum. mounts are 1/4" shorter than the stock mounts from the center of front bushing holes to back mounting holes. so if i were to use the shorter dog bones with these alum. mounts it would hold the engine forward 1.25" rather than the 1" if i were to use the shorter DB's with the stock mounts. but there is no way the engine is moving 1.25" inches towards the front, i cant get it far enough to line it up with the holes, sure i could force it but 1.25" is too much stress on them.

now on the other hand if i were to use the stock dogbones with the alum. mounts it would move the engine forward 1/4" over stock :)

reason im trying to move the engine forward is because of the vibration from lowering. after a few hours of driving it when had it lowered i did notice little to non of vibration so im just trying to eliminate that for when i install the lowering springs again.

im just not sure what combo to use, stock mounts+shorter DB's or alum. mounts+stock DB's i guess i could try both combos when the time comes and see if that 1/4" eliminates the vibration :p

now on the other topic about using 2 bolts on the mounts, i bolted them up and they feel solid as a rock! although i will need longer bolts since these are beefier than the stock mounts. other than that i dont think i'd have any issues using them ;)
i did have to grind them down on the bottom side though, so they could sit flush atop the cross brace.

(damn photobucket is acting up and wont let me upload my pics :mad:)

I believe they are in early 90's w-bodies (like the Grand Prix, Cutlass and a few others). I never measured if the spacing was the same, but I think they are adaptable. As I said, it was a thought I had, but I decided to stick with the stock dogbone setup.
You would have to swap both the dog bone and rad mounts to use the early w-body mounts (if they fit). I'd be curious what is the lighter combination and the pro's/con's of the two options.

http://i922.photobucket.com/albums/a...F/e618d905.jpg

Where I grinded them down flat from the bottom :p

http://i922.photobucket.com/albums/a...F/d6e07f28.jpg

Don't know of the pros and cons but I'll check them out, I'm on my way to the yard right now ;)

is this the one youre talking about jason? :p

http://i922.photobucket.com/albums/a...F/c3d49689.jpg

Yep. It's on a 3300 engine, so I don't know if the length of the dog bone is right for the 3400/3800 in the more modern W-bodies. This was something I considered for the quest of solid bushings (and again, the aluminum dones could be polished).
I think I gave up on it because:
- I did not like the look of the LONG radiator mount
- WBodyStore offered a sweet mount/bushing kit on Black Friday