Stock SU needles

[zeiss150]

Hey guys. What needles are stock in 72 240 SU's? The needles I have don't have anything stamped on them.

I've been running SM needles with stock nozzles and I was reading some posts here and "beandip" aka Gary has been screaming about how it will ruin the L28 to run SM needles. So now I don't know what the hell to do. so should I change to smaller nozzles or should I put the stock needles back in. HELP!!!!

[beandip]

I don't scream but I mumble a lot. The nozzles are alike for the round tops . Nissan had nozzles for the '70 240 . but only 6 in the USA . This was a few months ago. I am running 27 needles . I have a ZX flat top engine with 9.5 to 1 compression. A little more that middle of the road cam , which requires the higher compression . A ZX ignition , headers and 2 1/2 exhaust. Set at 10 degrees BTDC . The engine runs strong and just slightly on the rich side of right on. The color tune shows right on , for what that is worth. 27s are the needle offered for the '70 240 for performance . I was running 54s and they appeared to be a little on the lean side , looking at the plugs , so this is why I changed to the 27s . I have a brand new set of SMs if some one would like to buy them from me for $20.00 .