Think I will use ADS78506 next time as they 15mm shorter .
Another thing you can do here is a bit like bob was mentioning about drilling another hole.
If you drill another hole as close as sensibly possible to end of roll bar & use that hole for your link you are actually making the rollbar softer as you are changing (increasing in this case) the radial distance between the roll bar d-bush & the load point on the rollbar arm so rollbar will flex under less load (act like a thinner bar).
It is possible to extend/reduce the arms/drop link mounting point on standard rollbars & make the standard bars close rating to the whiteline simply by altering this length/leverage. For back ideally you need bit stiffer so reduce radial distance. For front you want softer so increase the radial distance.
Another thing you can do here is a bit like bob was mentioning about drilling another hole.
If you drill another hole as close as sensibly possible to end of roll bar & use that hole for your link you are actually making the rollbar softer as you are changing (increasing in this case) the radial distance between the roll bar d-bush & the load point on the rollbar arm so rollbar will flex under less load (act like a thinner bar).
It is possible to extend/reduce the arms/drop link mounting point on standard rollbars & make the standard bars close rating to the whiteline simply by altering this length/leverage. For back ideally you need bit stiffer so reduce radial distance. For front you want softer so increase the radial distance.