To all .
I haven't been a member for several years as too busy to do all things nice.
Anyway my chassis has the ability to sag in the middle which tend to make the doors rub on closing.
Can this be cured ?
Would heavy metal straps ( under tension /pre heated ) welded to bottom of the chassis help.
Or are there any tried and tested method of a cure.

The chassis can certainly distort - under jacking for example - but will normally recover when the point load is removed. If yours has a permanent bow this will be as a result of an accident or very severe corrosion, in which case it would be wise to remove the body and correct the distortion. If your doors are constantly rubbing, this is either a door hinge or body mounting problem. If the door gaps indicate the door has dropped, this can be corrected by removing the door cards and adjusting the hinge to door mounts; the mounting bolts pass through slots to allow realignment.

If the door gaps show that the door profile does not match that of the aperture in the body this can be probably corrected by adjusting the packing between body and chassis at one or more of the twenty-six mounting points - might be best to start at those in the region of the doors....

the question is WHY is the chassis sagging ... they are known to have some flexibiity as regards 'twist' ..but it should not sag in the middle. the worst enemy is corrosion.. if the chases is corroded to the point that is has been weakened there is only one viable and correct remedy :- remove body and fully restore or replace the chassis with a sound one.

You don't say which spec the car is, if B spec onwards then no, it is possible with an A spec especially if badly stored and or as Nick says misaligned when the body has been removed an replaced. However your post indicates that this is not a static problem and it is still moving, should the car be a B or C spec then you have a serious problem if an A spec then a close look for rot near the foreword rear spring hanger.

Hi John. I am intrigued how you have discovered the chassis is banana shaped? Or are you assuming it must be becuse the doors rub the B post? Syd