How to achieve this stance please?

Yep, you need some rear springs, air shocks or add an extra leaf. The previous owner of my Swinger added a extra short leaf to the rear springs. It looks like it came off a truck. It did raise the rear but it does ride a little firm. I would recommend new springs and if you want some lift, they can be made with 1 or 2" extra lift. I run 15x7 wheels on the rear with 255/60-15's and 14x6's on the front to get the look I want.

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Looks great! Any side pn shot please? What size front tyre? Thanks