I just received a rebuild kit from one of the Z parts sites and it had two different needle valves in it.  One is taller than the other.  Could there be a reason for two different sizes?  I didn't notice until I installed it and tried to adjust the float.

The front bowl goes low on acceleration so the longer one goes on the front to compensate.

There should be a R stamped on the short one.

Ztherapy sends both the same length. You add/stack washers to make up the difference.

Best thing I've ever done to my carbs was put two rear lids on mine, front and back

I got that right?

It's 2 rear lids that are shorter.

 

Edited February 26, 20223 yr by siteunseen

You got the good valves too! Mine have needle tips like the Schrader valve pin on valve stems of tires.

Who did you get those from if don't mind sharing?

When I tried to install the longer one, I actually had already rebuilt the front one with the shorter on (I hadn't noticed the difference yet).  When I installed the long one in the back carb, I didn't want to adjust the float tab so far to accommodate the length.  Tomorrow I'll pull the carbs and put the short one in the rear carb (by firewall) and the long one in the front carb.

Looking at the pic attached, I now remember that the set came with two sets of needle valves.  I installed the same size that was already in there.  Is there a way to know which one to use?

Thanks for the information.

I bought the carb set from zcardepot, but on Ebay.  

The ones you bought are the better in my opinion. The pin that rides on the float tang is closer to OE. A lot thicker and rounded off at the tip. The others are more like pins and more sensitive I imagine.

Here's a bunch of reading and pictures on the different valves.