Urethane motor Mounts, 1st gen Firebird, '69 Grand Prix, Some '60s A body and B body
 

In my internet searches, a few years ago I ran across these Polyurethane/Stainless motor mounts. They are perhaps similar to Butler's product (or also made by them for Butler?) While somewhat pricey, these should last much longer than the reproduction rubber mounts, and they eliminate the need for a turnbuckle because the steel parts interlock, but are isolated by the urethane. So a mid-point between solid mounts and the OEM style rubber mounts.

https://polybushings.com/images/PB2254.JPG

Interesting design, independent vendor perhaps worthy of support :thumbup:

https://polybushings.com/pages/2254.html

Been using these on my Firebird since 2012 no problems.

Do you have HO manifolds or headers? Have you noticed if the Polyurethane has had any issues (presumably minor since you appear to be pretty happy with these mounts) with the heat from the exhaust?

I have the 3” long branch manifolds I will give them a good look over when I put it on the lift and see if I can get some pictures.

Just wondering if these are the same $10 mounts made in china with a bolt added through them and then marked up 20 times. I sent those guys emails about there product to new hear from them again. What a rip off. I think they were called Mighty mounts. Here they are. https://www.mitymounts.com/howtheywork.htm

Chuckies, If you look at the Pontiac listing for the mitymounts, you will notice that they do not list mounts for the early firebirds, and their listing is incorrect for the '69 Grand Prix and other Ponchos with the pre 1970 non 5 bolt mounting boss engines, so clearly they are not the same.

It would appear that although they "mitymounts" have a part number listing for the earlier engines, they do not stock them (or make them). The ones from Butler may be by mitymounts, but if so they are not the same as those from polybushings.com - the method of construction is very, very different, at least based on the descriptions and limited photos on the mitymounts website. There aren't any bolts going from the face of the mount through the poly on the ones made by polybushings, it would seem that they interlock the stainless parts of the mount, hold them in a jig/mold to keep them apart, and pour in the polyurethane, let them set, open the mold, clean them up and sell them. Look at the different pictures: mitymounts:
https://www.mitymounts.com/images/dynatechtop_3.jpg

https://www.mitymounts.com/images/dynatechtop_3.jpg

verses polybushings


https://polybushings.com/images/PB2254.JPG
https://polybushings.com/images/PB2254.JPG

Very different indeed, and the polybushings are very, very beefy. I think Polybushings is a small US company making their parts in their own shop. I am not certain of this, but based on the information on their small website, and the focus of their product range, this would appear to be the case.

https://polybushings.com/index.html

Ya they do look different. I did purchase a set of these Mighty mounts back in the day when they were selling them. They are still on the car and working fine. But there just taking an offshore mount and putting a bolt through it. The polybushing look like a better mount.

I agree, that's why I originally posted the item on the board. They really only do unique/unusual, fairly low demand items, like these mounts and some Mopar suspension and engine mount pieces. They are what I bought to use on my 428 when it goes back into my restored GP body. I am just hoping that the polyurethane won't terribly increase the NVH through the frame, since I also have Poly frame/body mounts.

So I did confirm that the guy who builds these also sells them to a few vendors. His name is Johnny, he seems to be a great guy, a motorsports and unique car enthusiast. These mounts definitely feel like a quality product when you look at them. They are nothing like the mighty mounts, and are not made overseas. Given that my engine uses the long branch HO manifolds, I decided to come up with an insulated heat shield to protect the engine mounts from the manifold heat before re-installing the engine in the chassis. I will post pictures when I get it done.

I have the Butler poly mounts in my 69 bird which has LB manifolds. The poly on the passenger side mount has a little heat damage from the manifold. One thing nice about the mounts is they are thick so the oil pan doesn't touch the crossmember which is an issue with off the shelf mounts.

Do they still provide stock type vibration dampening?

I have not yet driven the car with them installed. I would assume that they fall in-between a solid mount and the factory rubber mounts.

I don't notice any vibrations but maybe I'm just used to it - car is tight though with the poly trans mount, front poly bushings, and Bilstein shocks.

I use these and they work great and do give you that slight added lift necessary for oil pan clearance. But I did melt one initially on the dyno and have since put heat shields on BOTH sides as I run Doug's headers.

It does sound like when I am reinstalling my engine, I will fabricate and install some thermal shielding to protect these from the exhaust heat - I am running the "long branch" HO cast manifolds in my GP.

I put the Butler mounts in my 69 T/A & wrapped them with insulating tape, as the passenger side manifold (long branch) practically rests on the mount. I now have great clearance between oil pan & frame, but am having trouble with exhaust leak due to downpipe not sitting flush on manifold (it's a Pypes 2.5" system). I'm suspecting the extra beefiness of the mount might be throwing off the geometry of the exhaust. Anyone else come across this issue?

DIY Polyurethane Engine Mounts
 

If you're feeling a little crafty, you can build a set of mount for under $100 that will handle anything you throw at them.

DIY Polyurethane Engine Mounts

Pontiac-DIY-Engine-Mount Gallery