Height of body

[chal340]

So Finally I adjusted the height of my mufflers.
In fact they were a little bit lower because I added a safety loop. I removed it for the moment. I'm going to design a new without touch on the exhaust line.
Like this I win more that 1". Now it's better with the speed bumps.

Adjustable hangers are solid to the frame and lift the front of the spring. The old school extensions at the back do lift the car initially. However, they also extend the pivot range as well. This then in short order allows the leafs to flatten out (de-arc). Resulting in no lift and ruined leafs. As noted I believe they also will hit rear valance when attempted.
Air shocks were also used, however these then transfer the suspension load to the shock towers. This area is not built to withstand that abuse and will also fail with serious structural issues.

Re arc existing springs or get replacements with a + arc.
Possibly a taller tire?
But definately I would tuck up the exhaust as much as possible. If you use headers it pays to have the right ones that tuck up properly. If exhaust mufflers are not factory type. Look onto making sure they are not oversized. As in too thick. More compact muffler also can help.
I like mine low. I fully understand speed bump issue.
Good luck.

Mike