Bump steer on M chassis

might there be other ways to solve this problem? how difficult is it to heat and bend the steering arms to the correct height and then retreat the heated area to the correct hardness? could heim joints be used instead of rod ends and then shimmed to the correct height? of course the steering arms would have to be drilled to eliminate the taper in the steering arm bore.
frank

I do not presume to have expert knowledge so please form your own opinion . I shall share our experience as it seems to be mysterious which it is not .
Firstly I would not bother with bumpsteer adjustment if I was only using the car on the road , it is probably close enough , it toes out under bump which probably helps turn in .
You can heat the steering levers and bend them . We did not do this as it would be difficult(for us) to produce two levers exactly the same and we would probably have different characteristics on each . Secondly if the retempering was suspect and steering failure resulted it would be wisdom in hindsight we do not need .
The simplest way would be with rose joints and shims as was suggested . We preferred to keep the tapered ball joint fitting , with the use of rose joints I would think a castellated nut and split pin would be essential as it would work loose in time and may become an issue .
We chose to use the TR4 steering levers because of the following .
They are shorter which improves rack ratio and the tie rods are virtually parallel with the rack . The tie rods left the rack with an angle towards the rear with the TR6 levers .
We have water pipes and oil cooler pipes running under the rack and it was easier to not lower the rack . Experience has taught that three steps forward mean two steps back and we did not wish to cut into chassis only to find we wanted to go back to where we started from , so opted to not cut into chassis .
There is a little bit of work involved , fortunately we have a reasonable engineering and workshop facility.
The TR4 steering arm levers have a smaller taper and will not accept the standard ball joint . We made a simple jig and used a lathe to enlarge the taper to suit . We then shortened the tie rods by 10mm each side . We them machined the threaded section of the ball joints to shorten them by 10mm as well . We then used a bottom thread cutter and took the thread to the full extent inside the threaded section of the ball joint , we then cut the locking nuts on the tie rods in half on lathe . These changes gave us enough adjustment space for toe in/out with tie rod lengths .
We fitted the steering arm levers with left hand side on the right and right hand side on the left , this necessitated making a longer spacer to clear the upright . The old spacer was 24 mm (sic) . we extended it to 33mm and fitted a longer bolt , this was on the bolt closest to the front of the car . we did this to push out the tie rod length and to reduce the ackerman ratio .
The rack then needed to be raised 12mm to achieve minimal bump steer . There was a spacer already under the rack 1.5mm thick , we did not know it was there until we had raised rack 12mm so just put it back in , it may well have been put there in the factory .
We still have not tested car so cannot comment as to driving results but the physics are correct so will be in the ball park . If not happy all the original bits can be refitted very easily and quickly so can go back to where we started very simply .

Looks like TR4 arms take a little fettling to make work, the easiest way to remove bump steer is still to fit 15" wheels and tires or lower your suspension until the arms are parallel with the ground.