A body mounts

[HARDCORE POSER]

I just pulled the body off my 69 Cutlass convertible and noticed that two of the mounts are more like spacers, no bolts thru them. Is there any advantage or has anyone switched these to regular mounts that bolt to the body? The car is getting a complete set of floors and cross braces so adding a couple of cage bolts won't be a big deal. Any and all feedback is appreciated.

[MrQuick]

sure, the more the better, are these the ones near the rear or the front of the car?
vince

[HARDCORE POSER]

They are under the rear seat and just in front of the rear axle.

[claytonisbob]

The body may not be very facilitating to add bolts in these locations (and not have some bolts sticking out in an eyesore location).

I wouldn't worry about it. You should already have an extra set of mounts right there at the firewall (4 total on the firewall).

[CHILI442]

This is a direct quote from another board. This was written by an engineer at an Oldsmobile plant in the late 60s and is in reference to the use of 2 and 4 body mounts under the cowl, but you get the point:

They played around with different combinations in development of the cars as is obvious by using only one mount at each side of the cowl, dummy rubber mounts (no bolt...compression only) at others and some nothing at all. It wasn't just cost reduction, it was ride quality on a particular body style.

The other factor probably is that maybe some other GM division (Buick, Olds, Pontiac, Chevrolet) share a common design in all or part of the frame design. The suppliers of the frames also would have some common tooling (jigs and fixtures) to build different types. They may actually have 4 mounts at the front and different combinations at the other locations...doesn't mean they actually got built that way at the assembly plants.

There are other things on the frames that may be used by other divisions and not Olds. The oval shaped hole in both sides of the front crossmember for example, even though only the ones on the passenger side are used by Olds, the fuel pumps is on the opposite side on one or more of the other divisions' engines.

Don't think it would hurt anything to put them at both positions at the cowl, but I wouldn't run right out and put bolts at all locations. Both the frame and body flex in operation and at static loading. There's no bolt there for some reason.

[HARDCORE POSER]

The cowl on this car only has one mount on each side, the frame has two holes. Do you think it's worth the effort to replace the mount pockets on the cowl with doubles from a Chevelle?

[Roadbuster]

In 1968, the GTO hardtop was available with an option called the Heavy Duty Frame for only $15. It was the convertible frame under a hardtop from the factory and used all the convertible mounts.

Wish mine had that option!