NewZed

Can't tell from your pictures if the brackets are swapped. The engines have a tilt to them with proper installation. If the brackets are swapped I think that it does bring the left side up, making the top of the valve cover more level. It can look correct but be wrong. The simplest way to tell might be to check the bottom of the oil pan. It should be level from left to right. Hate to say it and maybe, subconsciously, you already know it but it looks like that custom intake manifold could also be the problem. Where did it come from? Good luck.

Make sure you get a 280Z mustache bar to use with that 280ZX R200, it's needed. And the half-shafts if you don't have the clip-in style. Not clear what you're starting with. The other part of your "old posts" problem is parts availability. They're not as plentiful as they used to be. The 5 speeds and the R200's and the required mustache bar are getting harder to find. You can go aftermarket on the mustache bar but it's expensive. Finding parts might be your decision-maker. A junker 280Z might be a good way to get the parts. Good luck.

These words don't make sense. The valve cover is hitting the intake throttle body? Not sure what the effect is but sometimes people get the left and right engine brackets switched. I know it changes the angle of the engine. Not sure about height. Parts 6 and 7. https://www.carpartsmanual.com/datsun/Z-1969-1978/engine-280z/engine-mounting

Get it running and drive it. Probably not worth restoring. They are easy to work on. Service manuals are available to download on several different Z sites.

It will be interesting to see how things hold up. Are you using MIG welding? I assume that you are but you didn't say. There should be warping at each weld spot which might affect bearing wear since the inside of each cap is essentially a bearing race. Besides loss of heat treatment. Not trying to be negative, just assessing the odds. Good luck.

@Dat73z If you wanted some discussion about your recent post you'll have to post in a non-FAQ section. People can post new stuff in FAQ but nobody can reply. It's been this way for years, not clear why nobody fixes it or at least adds a note to new posters. You didn't say which u-joints were "too soft". That would be helpful.

Don't overlook the shield.

Might have better luck on classiczcars.com. More traffic and there are some parts traders there. Good luck.

Bumping zboi's thread so he can continue his contributions to the community. Let's see an update.

The internet is a great place to learn. Learn first, then speak. https://www.investopedia.com/terms/e/economiesofscale.asp Where are those dyno numbers? If the engine still runs.

I don't have Megasquirt but I know a little bit about EFI. Don't the MS data tables show injector open time? Duration? If open time isn't at 100% then it's not the injectors, it's MS not commanding them to stay open longer to provide more fuel. If they are at 100% then increasing fuel pressure should increase their flow rates. Sometimes on problems like yours it helps to break things down to the smallest elements. Analyze each step. What should happen versus what did happen.

RTPD = Read the post disappointed You should have created a fake name that at least leads to the mystery company. https://www.google.com/search?q=Flex+Engineered&rlz=1C1SQJL_enUS862US862&sourceid=chrome&ie=UTF-8

This part of the Megamanual might help. https://www.megamanual.com/begintuning.htm#spark https://www.megamanual.com/ms2/tune.htm

You have to look at your MAP tables. At high vacuum (low pressure) you can run more advance for a cleaner burn and better efficiency and better throttle response. At higher RPM under open throttle most people have found that about 34 degrees is where you get the most power. You can read a bunch in the L6 FAQ sub-forum about having timing set "all-in" at about 2500 RPM or various numbers around that. Meaning that it stops advancing and just hold at that advance number from there to the high limit. If I was starting with an MS tune I might first just mimic a stock engine's timing curves. Nissan provides them in the Engine Electrical chapters. You have to do some translation. And the charts are in distributor speed so that's where you have to do the doubling. From back in the days when they had distributor tuning machines. The early FSMs have an actual graph. Later ones have just a table and let you imagine the lines. Here is 72 and 78. 78 would be like your engine probably if it's a stock 290Z engine. They have different options for different markets and different transmissions. Generally, lower advance is for emissions states, like CA. Reduced timing is cleaner. notice that they give the starting point, zero degrees at XX RPM. So the first entry shows vacuum advance starting at 200 mm Hg, and increasing to 15 engine RPM at 350 mmHg. Centrifugal starts at at 1200 RPM and rises to 17 degress at 2500 RPM. It's like a mini general physics course. It can be confusing, especially since centrifugal is tied to crankshaft rotation but vacuum is just tied to air pressure in the manifold. Sometimes I still wonder if I'm thinking about it right. It's easier to grasp if you have a stock distributor on a running engine with a timing light to learn on. Good luck. 1978 EE chapter. 1972 EE chapter.

Not sure exactly where you're going or what the current problem is, but I think that the first comment above is incorrect, and the second one is correct. Also, you were talking about cam timing and ignition timing together at one point (the 4 degrees thing). They are completely separate as far as spark goes. You could move cam timng all over the place by switching holes on the sprocket and it would not affect when the spark occurs, relative to crankshaft position. Timing sensors are all measuring where the crankshaft is in its rotation. Cam timing is also relative to crankshaft position but adjusted separately from ignition timing. Just some hopefully helpful commentary.