Starting to go over my 88 vert. I put it on the lift to get a look under it better and my door jam gap opens up about 1/4-3/8”. Doors still open and close fine. Would this be considered normal flex or excessive? It doesn’t have any rust except for a small spot in the driver floor pan - vert top leak I am guessing.

 

1/4 is a lot, let alone 3/8.Maybe thats "normal" for the verts, but regardless thats a bit much.Do you have any structural support added?

 

No, all stock. Remember it is a t too car with the top bracing cut off.
My meaurement is a guess. Just sticking my finger in the door jam with it on the ground and on the lift.

 

Any flex is excessive, the sooner you remedy that the better.The closer you can get it to zero flex, the better.

 

Time for some Alston subframe connectors

 

Subframe connectors were my first thought
need to get some real measurements and see how much it is really flexing

 

You don't really need to measure the flex for anything except curiosity. Just get all the chassis bracing you can get your hands on. SFC's, Wonder bar, etc.

 

I added Spohn tubulars and they made a huge difference on my factory convertible which has a lot of bracing added by ASC already.