Problems of solid mounted body.

[T.K.]

Any problems I should be concerned with by welding my body to the frame or using solid body mounts. I know some people think that ride quality may suffer or that I may feel more of the motor. I recently heard that people have had paint crack, bond pop, and windows break. I've never seen this first or second hand. Anybody think their is any real concern of going solid?

[77thor]

I've been running solid aluminum body mounts on my Camaro for years with no issues.
They really don't affect ride quality, the shocks do.

The engine vibrations are taken care of by the motor mounts (you don't want solid mounts there).

The comments you've heard are all backwards; "...paint crack, bond pop, and windows break..."
are all caused by the body flexing, which solid mounts will help to prevent.

[71RS/SS396]

Why weld the body to the frame? I would just use solid mounts and bolt it together so it can be disassembled later if need be.

[79T/Aman]

"...paint crack, bond pop, and windows break..." it is kind of funny how the internet has given new life to old wives tails

[T.K.]

@71RS: Simply because the car does not have mounting hangars. It is a fabricated full frame chassis and the body is a 68 F-body. The mounts went with the floor.

[T.K.]

Inner rockers chopped and replaced with straight 16ga plate. Body solid mounted to frame from farm rails to rockers. Solid mounting the rear of the car to the chassis is a bit trickier with no trunk pan or wheel wells, but may be done today. Thanks 77thor for the confidence to go this route, this car is going to handle like its on rails

[astroracer]

Inner rockers chopped and replaced with straight 16ga plate. Body solid mounted to frame from farm rails to rockers. Solid mounting the rear of the car to the chassis is a bit trickier with no trunk pan or wheel wells, but may be done today.

This "little" bit of information would have been good to know in your initial post. This is a big deviation from the solid "subframe" mounts any reader would have understood without this knowledge.
Just remember the floor pans on these unibody cars carry most of the structure. When you cut this stuff out you really need to look at adding that support back in "somewhere". If you don't you will run the risk of sagging body panels and non functioning doors. Tieing the rear of the roof/bottom of back window into the upper cage will add that structure back. Tie the tail light panel into the rear of the frame to carry the trunk and fender loads.

[T.K.]

Understand. Tieing butt to frame is already in progress. Steel floors will go in next, then the cage. I was relying on the structure coming from the full frame and cage vice the unibody, but I definitely want to tie to the body where needed for extra rigidity, and more importantly as you said to keep the body shape correct.