Yarb

@siteunseen, Does that product need to be neutralized after the application?

Could it be an early version of a Neutral safety switch?

Much appreciated, I’m sure other’s will benefit from it as well.

The dimensions you posted earlier were wider which is odd. Thought the 240 boosters were smaller in size. One other thought. The 15/16 booster sold by Cardone on Amazon is New and not rebuilt. Read a lot of reviews on other sites when combined with the ZX booster the pedal feels more like stock where the wilwood was a much harder pedal. Just a thought here’s a pic of what I purchased. $65. Not trying to persuade you by any means. Just a few options out there. Curious to what you find when you get home.

Hope this helps. Let me know if there is anything else You need.

Ok, Here ate some pics of my 1978 OEM booster. The dimensions are: Top horizontal stud dimension left to right. center to center. 3 5/16” Vertical center to center 2 3/4” Overall booster diameter 9”

Definitely 79-81, Bolt pattern 180 degrees out on 82-83. I purchased mine from Power Brake about 6 months ago.

You may have seen this on eBay already. If not I found this. Could be a good candidate for a rebuild.

Use some 400 grit Emory cloth. Need to get everything down to bare metal. Including inside the eyelet of the cable.

@Captain Obvious In Your spare time😀.Would you be kind enough to create a rough schematic of your relay install. Also curious on where you located the relays. I’m waiting on other parts to arrive so this would be a good time to go ahead and do the headlight relay upgrade. No Hurry of course!!

What option did you decide on for lowering the car?

Possibly, FS5W71B. 81-83ZX ?

Inexpensive to replace, Easy to get to with the booster out and your already under the dash side by side with the pedals. With it being dry the slave cylinder could be leaking as well. Pull back the dust cover and take a look.

Jeff, I believe these two pics show the location @EuroDat is referring to. Pics 2&4.

Here’s a couple pics off my 83zxt engine I bought. Haven’t verified it but this might be it.