Shorter shocks won't help. It will still hit (and cause the bang) on the bound bumper and/or the top of the tires. When lowering 2" you take away the suspension travel.

Thanks for all the help chaps i reckon it's the shocks as you say. I took a look at the tomei car as it went over the pits [youtube].I think i mounted the bottom bolt to high so there's hardly any travell. Thats what happens when you want to take the easy way out.AND that is on top of the 50mm block instead of at the bottom.[mounting]Sorry forgot to say it's a alfa junior lsd so no bump stops and thats the reason i got the block in.It's taken out approx 20-25mm so that the axle can lay in it.SOOoo i'll change mounting and see what happens.thanks all

If you haven't modified/removed the rear bump stops, then the rear shocks won't be too long. It is the bump stops that determine the amount of travel available.

A flipped leaf and 50mm blocks will mean you have bugger all travel before the diff hits the bumpstops. What model is it? There are differing bumpstop setups between coupe, ute and sedan.

To regain some lost travel you will need to shave the bumpstops down and then yes, you will need to check to see if the shocks are bottoming out before it hits the bumpstops.

i'd go with shocks bottoming out, the springs wont have really changed to much in the stiffness as you haven't added any leaves or changed any, stock shocks would in no way would cause that much of a jolt due to compression rate being too high.
maybe unbolt your shocks from the bottom nount, cable tie them out the way and go for a drive over said 'calming area' and see hou it feels, if no sudden jolt start your search for some shorter shocks :)

Coil over rears need major re enforcement of the shock top strut metal in car.
If you reckon flipped leaf hard try coil overs lol.
I reckon more to do with the 50mm block and stock shocks bottoming out.
That means you need short travel shocks

I was driving around block to test some changes and had to go over speed-bump or as they say here 'calming area' sh-e-e-t man a real jolt up the spine.the 1200 has std rear shocks,1 leaf flipped and 50mm block[new shocks-nothing special]have'nt really put it to the test but i reckon this must be to hard & it's prob. going to bounce around a bend/cnr. I was looking at tech wiki and sort of like the idea of the main spring and adj.shocks. now can i still use same block[50mm] and what shocks, weightand length depending of course on mounting points.Lets put it this way which shock is closest for upright or slight angle mounting