I'm getting a 1970 car running again after 9 years. Interior is redone, engine is now running. Rebuilding brakes right now, working on clutch next. Noticed some gray chunks at bottom of shocks today when putting calipers back on. on both front right and left. Seems to be foam (stuck my finger through and one of the chunks just disintegrated).

So what died here, and maybe more generally: what should my shopping list look like for getting car back in shape, as far as the suspension is concerned? I'm not worried about trying to keep car stock. Wouldn't mind if it say a bit lower than stock, as long as that helped it corner a bit better, but it's not a big deal to me one way or the other. Would appreciate any recommendations, and also warnings if some procedure is risky for me to do myself. Practically everything I know about working on cars I learned on this project, so if you assume I know nothing and am a drooling idiot, you're not going to offend me.

The foam might be the remains of an "ASSY-BUMPER BOUND". AKA bump stop. I've never seen one myself.

http://www.carpartsmanual.com/datsun/Z-1969-1978/axle/front-suspension/46

Lowering spring options seem limited. There used to be some choices, like Vogtland, but I don't know what's out there today.

This is maybe a modern alternative? Doesn’t sound like foam to me. https://zcardepot.com/products/strut-bump-stop-poly-240z-260z-280z?variant=31994410336369&currency=USD&utm_source=google&utm_medium=cpc&utm_campaign=google%2Bshopping&gad_source=1&gad_campaignid=17820837536&gbraid=0AAAAADgHqXubWS9vzOZNsLdNoFCRC4Msa&gclid=Cj0KCQjwteTUBhD4ARIsAEYjs3qiOWp8hezXGBa0n2MG2spTJOGrIwF7mBO42Ki_2Jx9OU-R9_g4aMMaAid9EALw_wcB

Reading up on procedure for installing new bump stops. Seems like a good time to also replace the shock inserts? Front and back while I already have the brake lines drained? Are the KYB ones at zcardepot recommended?

Many people don't use bump stops. I think that those hard polyurethane stops probably limit travel. By at least an inch, I'd guess. There used to be another option out there, of softer foam. Can't remember the brand.

Are your shocks/struts original or have they already been changed to inserts?

KYB shocks worked well on my 76. They seem to have a good reputation around the automotive world. I put them on my truck, They work great. They're cheaper at RockAuto.

https://www.rockauto.com/en/catalog/nissan,1970,240z,2.4l+l6,1209147,suspension,shock+/+strut,7556

Might have been Koni. Probably in one of these threads.

https://www.google.com/search?q=site%3Aclassiczcars.com+bump+stop