They do put in different needles that run more rich. I am not sure that it is part of the basic Ztherapy SS treatment, but I requested them.

I get the impression that the performance in the SU's is mostly due to the correct needle selection and the weight of the oil in the piston. You can control how fast it rises and how much fuel comes out. Until you reach the max CFM the SU's can flow with the pistons fully up, I think you can tune to just about any reasonable performance level.

I used a 1/2" pipe plug in the thermostat housing IIRC. It's an allen head plug (socket head plug?) so it sits flush in the housing.

I went out and measured the threads and on my '72 it is definitely a 1/4" British Std Tapered Pipe Thread so you would want a 1/4" BSP plug, yes? Outer diameter of a 1/4" BSP is just over 1/2". Main thing is not to use a 1/4" NPT plug which has a different thread per inch count.

I went out and measured the threads and on my '72 it is definitely a 1/4" British Std Tapered Pipe Thread so you would want a 1/4" BSP plug, yes? Outer diameter of a 1/4" BSP is just over 1/2". Main thing is not to use a 1/4" NPT plug which has a different thread per inch count.

On my '73 I am pretty certain my thermostat housing is 1/2" pipe (or similar, and definitely way to big to be 1/4 NPT). Reason being I removed a pipe plug from a junk LT1 water pump and it threaded into my housing by hand until taper prevented further tightening. I went "sweet!", wrapped the plug with teflon tape, restarted the plug by hand, and tightened.

In my experience, a different TPI would not allow for tightening by hand or anything else. It's been installed and sealed since I did the header in early September. Maybe something subtle changed in 73? I really don't know, I'm feeling like I got away with a ghetto fix :stupid:

Thinking a little more, did the 72's have EGR? The water lines on the 73 go to both the EGR and intake manifold. Maybe they changed to 1/2 NPT to allow for more volume/flow

UPDATE:

All parts are on the car. I did not get around to finally torquing the bolts. There is no way I will be able to get a torque wrench on the bolts below the intake, so I will have to use the force.

This is shaping up well. I still have some cleaning to do on the block and run new fuel lines. Still have not figured out how I want to rerun the coolant lines. MOre on that after Turkey day I guess.

The couple hard-to-get-to nuts I had to use a 1/4 drive universal on an extension. Obviously not ideal with a torque wrench but it was the only way to truly control how tight the nuts were. I actually used an inch-pound torque wrench that was 1/4 drive. I understand not everyone has access to an inch-pound torque wrench but it was much easier than a larger torque wrench

I can understand you had to put the carbs on to see how they look but it will be much easier to torque everything with those removed.

btw, looking great

On my '73 I am pretty certain my thermostat housing is 1/2" pipe (or similar, and definitely way to big to be 1/4 NPT). Reason being I removed a pipe plug from a junk LT1 water pump and it threaded into my housing by hand until taper prevented further tightening. I went "sweet!", wrapped the plug with teflon tape, restarted the plug by hand, and tightened.

I agree. Mine is definitely NPT, and I'm pretty sure it is 1/2".

I bought several plugs yesterday. I know one fit very nicely, threaded in with no issues at all. I will see which one it was. I think it may have been NPT.

As far as the carbs go. They were installed by Ztherapy on the manifold when it arrived. I just bolted it up. I may have to remove the carbs to get a good torque on the nuts. I think a 12mm crows foot would help dramatically as well.

Quick note. It seems I made a bit of a mistake when putting my thermostat back on. The spark plug wire holder that bolts to the rear most bolt on the thermostat cover is made of plastic, and when I put it back on, I sort of snapped the plastic in half. Does anybody know who may have an extra?

On my '73 I am pretty certain my thermostat housing is 1/2" pipe (or similar, and definitely way to big to be 1/4 NPT). Reason being I removed a pipe plug from a junk LT1 water pump and it threaded into my housing by hand until taper prevented further tightening. I went "sweet!", wrapped the plug with teflon tape, restarted the plug by hand, and tightened.

Looks like we have different housings!

Looking further at the film, it would make sense to increase the ID of the plumbing to deal with the fact that downstream your Z is supplying the EGR and the Carb while mine is only doing the carb. Having a NPT thread is a real plus as you can install a standard 1/2" NPT thermostat switch for an electric fan.

Quick note. It seems I made a bit of a mistake when putting my thermostat back on. The spark plug wire holder that bolts to the rear most bolt on the thermostat cover is made of plastic, and when I put it back on, I sort of snapped the plastic in half. Does anybody know who may have an extra?

Part 33, Nissan number 22472-E3000, still available from Nissan for around a buck and a half. Same price roughly from MSA. #12-4181.

You know for whatever reason, I was looking at the cooling part of the catalog since that is where its attached to the engine.

Sometimes, I really have to think I am starting the road to senility early.

Ordered my new wire holder today, and since its just plain silly to just order something for $1.53, I had to add a new european curved dizzy. I am hoping my current pertronix will bolt into the new dizzy.

Yes, I am weak, and like new shiny OEM parts.

But HEY, its Christmas soon, Merry Christmas to ME!!!

Ordered my new wire holder today, and since its just plain silly to just order something for $1.53, I had to add a new european curved dizzy. I am hoping my current pertronix will bolt into the new dizzy.

Yes, I am weak, and like new shiny OEM parts.

But HEY, its Christmas soon, Merry Christmas to ME!!!

What's this distributor that you speak of?