Finally installed both front and rear shock absorbers, I used KYB rear ref 551045 and front 343022, huge difference in ride and cornering, existing absorbers were old (too old) bushes cracked etc, also rear absorber would stay compressed ie was not double acting, so if you are installing you need to wire up the rears in a compressed state to get them in. One bolt rounded off so bolt had to be cut off with grinder.
One absorber was set up with washers in place for bad road and the other rear normal, note correct position for washers and rubber bushes as its easy to get wrong also one of the washers is thinner and needs to go against the middle plate, thicker ones at the ends to retain the bushes.
Front absorbers Hayens write up is wrong for later 4GTLs,you dont have to move cables and there is no top cup to unbolt, front and rear are easy to do, but you may have to bump the front of the car to get the absorber in whilst jacking the stub axel. You have to remove the front roll bar, the bush that it is pushed into can be set one of two ways, one has more projection than the other, mine were set for the lesser projection but were fouling their support and the roll bar ends were only just into the rubber so were wearing the holes too much.
However after all that the rear wheel was still rubbing the rear wing on cornering with a passenger in the rear - so we grinded 5mm off the lip to the bottom of the wing and problem solves what was the cause who knows - torsion bars, car twisted, rear wing slightly off when restored.