IAG Short block Troubleshooting, help with new build

[BuG3y378]

Hello everyone. I'm in a bit of a dilemma here and wanted to get some advice. I've had some issues with my ej257 swap into my bugeye and long story short I've learned a lot doing this by myself mostly and made some mistakes along the way.

I have taken the engine out a previous time due to what I thought were leaky valves and just had the "newly rebuilt" heads re done again. Only to reinstall and have a similar problem low compression on another cylinder and no power.

I had lower compression on cylinder 3 (135) compared to 150 across the others with a new iag stage 2 tuff block. My heads were bought freshly rebuilt however, upon doing a leak down test they had some issues. Therefore, I decided to get new out front Motorsports heads .

I have now replaced the heads and gotten everything back together on my engine stand.
I wanted to perform a compression test with it on the stand however, mine is an automatic and I am unable to find a bracket that will allow me to lint my starter properly. I 3d printed one from the Subaru only YouTube channel but, it must be a bit different mounting wise from a manual to auto.

I performed a leak down test again while on the stand and it seems ok but, getting some leakage at the spark plug hole at almost 100psi (probably because I have a harbour freight tester). I did hear a little bit of air from the oil spout on cylinder 3 but, not a lot.

Some more context on how it was running during these issues. It started an ran however clearly want running on all cylinders. Very low power and would backfire some. It also had a decent amount of smoke (maybe running too rich?)

Thanks in advance