If you have a 1974 B210 with an A13 engine, then you must be in the USA

It's probably a good idea to include your basic profile so that later on you wont have to keep telling people that ask.

If I remember rightly, the US B210 used brakes that are slightly larger than the 1200 & I do not know if the 1974 model used the full US front suspension that I believe later models did. Something different about them.
I'l just sit back & wait for some of our US mambers to kick in & perhaps I can learn something.

Over here there is a lot of stuff available for our version of the car, known as the 120Y & unlike the US it came only with the A12 [1171cc] engine.

You should be able to have your rear springs reset to the new ride height by a local spring works.

For interests sake, there were two different A13 engines. Yours is the first of the new generation 'tall deck' or stroker engines. It still retained the smaller 73mm bore of the 1200 engine but a new 77mm stroke.

There was another A13 that appeared in the Asian "Sunny" B310 [equal to the US '210'] This one was based on the low deck engine & used the shorter 70mm stroke of the 1200 engine but had a bore size of 76mm.

If you don't already know, your chassis will accept the later A14 & a15 engines straight in
A14 = A13 but with 76mm bore
A15 = A14 but with longer 82mm stroke