Body mounts on new chassis

[LS1 Grand Prix]

I am building a new frame for my LS powered '81 Grand Prix. It is 2 x3 box, Mustang II front suspension, coil over all around with 4 link. My question is about the body mounts.
I will be loosing the mount at the front of the rear wheel wells due to putting in wheel tubs. The center mount falls out in the center of the frame rail. Does anyone have an opinion about loosing this mount as well.That would leave me with 5 mounts per side.

 

[Streetbu]

I wouldn't lose either mount. G bodies need all the help they can get

 

[superbon54]

Sweet setup!!! On a stock frame, the body supplies a significant amount of the torsional rigidity, which is why t-top cars flex so much. With a properly built box frame alone you’ve probably got more rigidity than the stock chassis/frame combo, but you will lose some taking a few mounts out.

Aluminum bushings or hockey pucks might be necessary to eliminate sag of the body shell if you go that route.

If you’re looking to maximize torsional rigidity, you’ll need to cafe it no matter what.

 

[GuysMonteSS]

I am building a new frame for my LS powered '81 Grand Prix. It is 2 x3 box, Mustang II front suspension, coil over all around with 4 link. My question is about the body mounts.
I will be loosing the mount at the front of the rear wheel wells due to putting in wheel tubs. The center mount falls out in the center of the frame rail. Does anyone have an opinion about loosing this mount as well.That would leave me with 5 mounts per side. View attachment 153396

Nice looking job by the way !!
Guy

 

[UC645]

Losing those mounts on a stock frame would be a bad idea without a cage. That being said, the frame you’ve got there is fully boxed and is most likely made of thicker, higher quality metal, so it’ll take up a ton of slack that the stock platform had.
Just move the body mounts further towards the center mount and keep the center mount. Adding some extra bracing to the body wouldn’t hurt either.

Sweet frame by the way!

 

[LS1 Grand Prix]

Losing those mounts on a stock frame would be a bad idea without a cage. That being said, the frame you’ve got there is fully boxed and is most likely made of thicker, higher quality metal, so it’ll take up a ton of slack that the stock platform had.
Just move the body mounts further towards the center mount and keep the center mount. Adding some extra bracing to the body wouldn’t hurt either.

Sweet frame by the way!

Thanks

 

[LS1 Grand Prix]

Losing those mounts on a stock frame would be a bad idea without a cage. That being said, the frame you’ve got there is fully boxed and is most likely made of thicker, higher quality metal, so it’ll take up a ton of slack that the stock platform had.
Just move the body mounts further towards the center mount and keep the center mount. Adding some extra bracing to the body wouldn’t hurt either.

Sweet frame by the way!

Thanks

 

[LS1 Grand Prix]

Sweet setup!!! On a stock frame, the body supplies a significant amount of the torsional rigidity, which is why t-top cars flex so much. With a properly built box frame alone you’ve probably got more rigidity than the stock chassis/frame combo, but you will lose some taking a few mounts out.

Aluminum bushings or hockey pucks might be necessary to eliminate sag of the body shell if you go that route.

If you’re looking to maximize torsional rigidity, you’ll need to cafe it no matter what.

Thanks

 

[fleming442]

In this day and age of suspension technology, why the hell would you put a Mustang II front end in it?

 

[pontiacgp]

that is a nice jig, did you fabricate it or buy it?