SeafireXV

To keep the advice simple: The 240Z has the magic name, the early 260Z is the last of the lighter weight chassis's, and the 280Z is the most numerous and easier to find.

An assembly line goof?

260's began production in July '73, so all 260's and 280's will have the same rack. Maybe some of the last 1973 240's also, depending how late they were in production.

About ten years ago I purchased a never-been-used E31 with bigger valves for my L26 and I paid $500. I felt that this was a good price for an unused head. The thing to watch out for is warping and how much the head has been shaved, almost a certainty for a 45 year old aluminum head. You will have to bring it to a good machine shop for the measurements.

You will always get some squat on a car with independent rear suspension. Its just a part of the mechanics involved. I suppose the stiffer the spring, the less squat on acceleration. ZX's have more exaggerated squat because of the type of IRS, namely semi-trailing arms vs. Chapman struts on the S30. Swing axle IRS will squat even more.

The same header fit for 1970 through 1976 model years. 1977 and 1978 models had the round exhaust port heads, so the headers were slightly different to accommodate the port shape. I don't know much about ZX's, so I won't guess.

A 65 Mustang, a 74 260Z, and a 99 SVT Contour.

unfortunately, the creaking sound is just part of driving a Z, sort of like the unique aroma of a British car. Many have tried to eliminate it, but it never goes completely away.

There are six factory approved jacking points on a Z. The four points on the rocker panels, the front chassis cross member for lifting the front wheels, and the diff for lifting the rear wheels. As long as the body is not rusted to the point of failure there are no problems with using the diff as a jack point, and you should never lift the car using any other jacking points.

I counted at least 57 brand new Z's in that photo!...........mmmmmmm

That is close to being what we considered the "Holy Grail" for Z's back in the 70's. A series 1 red car with black interior. That's an early series 2? Its in fantastic condition, especially for a rust-belt car!

The factory shift knob is shown in post #3, anything else is an aftermarket knob added by the dealer or by an owner.

Another SU trick is to remove the plunger/dip stick thingie that's attached to the screw cap on top of the carb. My friend did this to the carbs on his G prod Spitfire that he raced back in the 70's and 80's. It improves throttle response quite a bit, similar to removing the spring, I guess. Probably wouldn't very well on a street engine

Any 20w oil will work. That's what all cars equipped with SU's used from the factory. There is even a specific brand of SU dashpot oil still available in the UK. I tried 30w oil in my carbs for a while and it made them run too rich. Terrible gas mileage and lots of exhaust staining, although the car ran fine otherwise.

If performance is your main goal all you need is a good quality header, either stainless steel or coated to take care of rust. A single exhaust pipe no more that 2 1/2" diameter and a good quality free flowing muffler like Flow Master or Magnaflow with a single outlet tip. You don't need a resonator on an L28 as they are not as raspy as the L24. Just use common sense and keep it simple. Z's seem to respond well to simplicity. Dual pipes are not necessary and just complicate things, and period mufflers like the Monza dual tip setup are more for looks than performance. Anyway, that's what I've learned over the last 40 years.