First off, thank you for the help!

So I ran the compression and leak down test (leak down was a first time for me, so hopefully I did it right, I used this tester: https://www.amazon.com/dp/B0030EVL60 ). I only ran the tests on #1 and #2 as I am a little short on time right now and the rest requires extra disassembly.

Max Compression Cyl#1 190psi Cyl#2 195psi

Leak Down @ TDC:

Cyl#1 @75psi->73psi...3% leak down @90 psi->87psi...3% leak down (I ran this cylinder 3 times and got the above #s twice, Because my first go I was getting 7% and 11% so I probably missed TDC and wanted to confirm after comparing to #2s results)

Cyl#2 75psi->72psi...4% leak down @90 psi->86psi...4% leak down

So this all seems normal to me and consistent, but I would be curious what you think of you have the time.

Thank you for taking the time to help me this far!

First off, Thanks for all your help!

So I ran the compression and leak down test (leak down was a first time for me, so hopefully I did it right, I used this tester: https://www.amazon.com/dp/B0030EVL60 ). I only ran the tests on #1 and #2 as I am a little short on time right now and the rest requires extra disassembly.

Max Compression

1 190psi

2 195psi

Leak Down @ TDC:

1 @75psi->73psi...3% leak down

@90 psi->87psi...3% leak down (I ran this cylinder 3 times and got the above #s twice, Because my first go I was getting 7% and 11% so I probably missed TDC and wanted to confirm after comparing to #2s results)

2 75psi->72psi...4% leak down

@90 psi->86psi...4% leak down

So this all seems normal to me and consistent, but I would be curious what you think of you have the time.

Unfortunately I dont have the time right now to take the whole intake out to inspect into the cylinder while hot.

I do have a lighted borescope camera, do you think I would be able to see the pop leakage on that via the spark plug hole?

Thank you for sharing your wisdom!

I fought this problem for a long time, is your coolant overflow bottle filling up with coolant by chance, and is your radiator looking empty when it happens? If so, you have a blown headgasket. You want to do a leak down test on your motor, it's really easy to do, and will save you years of headaches. The plugs you used, didn't come from amazon or ebay did they? When is the last time you did a valve adjustment?

Things that can cause misfires: PCV Valve, valve adjustment, incorrect spark plugs, oil getting into the cylinder because your valve cover gasket is bad. Leak down test will give you a good solid idea of what condition your motor is in, before you start pounding more money into it.

https://www.amazon.com/dp/B0030EVL60?ref=nb\_sb\_ss\_w\_as-ypp-ro-model\_ypp\_ro\_model\_k0\_1\_10&crid=2LNMHXRA53RIS&sprefix=leak+down+

Ill do a leak down test. Never done one before. What is your opinion on this product? https://www.amazon.com/OTC-5609-Cylinder-Leakage-Tester/dp/B0030EVL60

And yes, I could just scrap this engine and upgrade. I was excited to make this m20 into a mild stroker and want to salvage as much as possible. Also for the experience, since I'm fairly new to working on cars. But I agree that if I keep finding problems there is a point where I need to cut my losses and figure out a new plan if I ever want to get this car back on the road.