How much damper Oil should be in the Su carbs? there is some in my carb but not a whole lot that i can see? and what conditions would that cause?

SU's don't hold much oil. A few cc's at best. You won't "see" the oil, but it should show up on the dip sticks, there are lines on the stick to mark the level of oil that should be in there.

Lack of oil will cause the piston in the SU's dome to rise too quickly causing harsh throttle response, and probably more that I don't know about.

Dip sticks are often traded or mixed up from a 240z to 260Z over their past 20 to30 years of life. The barrels at the end of the stick are the same diameter but the stick length may be a little longer on a stick from a 260. Either one will work fine. You should see the oil level between the 2 lines on the stick which will work fine. I think the oil chamber inside holds about 2cc to 3cc of 20SAE oil.

I fill mine up to just below the lip of the piston that you see when you look into the top.When you put the sticks back in it will push out any excess.I use marvel mystery oil or autotranny fluid every now and then because the excess that runs out cleans the gunk from the piston body.I also have replaced my sticks and carry the old ones in my car.I heard of a guy once that one of the plastic screw tops broke and left him stranded.AS we know you would never find a replacement in a hurry unless you had it with you.

if you add too much oil to the dampers the excess will just be burned by the engine , no big deal. Recommended by the builders of the Z is 20 wt . , I have tried auto- tranny , mystery , 3 in 1 oil and the best so far is 20 wt. the lighter oils cause the piston to rise too quickly causing a lean mixture and in my case a slight stumble off the line at a normal throttle, like from a signal . I kept thinking ignition . I found a source at the Cycle shop ,it is used in the front forks on a cycle. Ask for fork oil. "Try it youll like it " . I have herd of users trying brake fluid ,water, all sorts of combinations , if you know more than the designers try anything. :classic:

Would power steering fluid be the same as fork oil?:cross-eye

No, Power Steering Fluid is NOT the same as fork oil. It MAY have a similar viscosity, but is substantially different. You might try using it, but I don't understand why you'd want to. Fork oil is SO easy to get, and works well.

Just my $.02

Carl

In the Nissan service manual...it lists Castrol 20wt as the primary and Castrol 10w30 as an alternate oil. Just some food for thought.

power steering fluid is automatic trans fluid, the same thing. Much thinner than 20w . it is the viscosity that makes the difference.