Hey Tom.....
Glad to see you twisting on your Z!!!!
I've heard so many things about this...... Stormin Norm, uses 3 washers and no oil, no spring in the dampers, Seriously. Runs 12.8 quarter miles with a su, carbed 2.8 litre 240z..... My present car came with no oil at all in dampers, but with springs...ran great for 1 and half weekends til I ground off a cam lobe, and pulled the engine. But ran rich occaisionally, but otherwise made decent power... My present engine, a sunbelt build from 2005 has a fairly thick oil that really restricts piston movement....I'd guess 10w or so. Motorcycle fork oil, castorl oil, mineral oil, engine oil, tranny fluid, brake fluid. I've heard all of these, being the thing to use...... Likely temperature related to optimum vicosity needed..... Check out the videos on ZHOME.com showing the piston doesn't ever open fully.... So don't want'em flopping up and down wide open......

david