91 MM not starting

I got into truck..

'91 MM 4g64 sohc Fuel injected

It turns over really easy, I took a spark plug out and stuffed a bit of towel in there and turned it over to check compression.
*pop*
- maybe not the most sophisticated or accurate method to test with but at least its something.
Oil looks ok
Got the fuel pump to engage finally I think
- there's like a 10 wire connector under the passenger side seat that was disconnected, why its under there or unplugged idk but it goes to the pump, that works now
- good job Indigo
Fuel at the fuel rail, new filter, and there's spark from dis
I think the timing could possibly be off one tooth.
- Pics include: first the timing marks lined up on the upper pulley (I learned that was the true mark some sticky here), second is the timing on the lower pulley when the upper marks are lined up. Its like 15° off...
Last and weirdest
There's a freeze plug on the backside of the head ([Bwhat size is this thing[/B]???) that I assume goes to the water jacket? When I poured water into the system it liked to cone out that hole
- It's totally open
How? A good question. maybe out it popped under intense load/heat? Its totally clean except on the inside - Its gunky oily and smells a bit like gas.. also the spark plug I pulled had a drop of water on it.
The mechanic in me says its green eggs and spam
Looks like a nice truck I might just take the eci multi off and stick it in my 89 d50 I don't want to tho, I'd rather have a second truck

Thoughts?

Thanks
Indigo

Figured out a few things except what this freeze plug is really for...
I'm pretty sure it's supposed to go to the water jacket in the block but the problem is when I hold my hand over this homme while the engines cranking it has pressure on it from the exhaust... bad.

Oh but the timing was off one tooth, I figured that out and now at least it tries to fire but won't because I pretty much determined that it doesn't have compression. Anyways is this in fact the water jacket freeze plug

There could be all sorts of nasty stuff going on with this engine. Bad head (most logical due to oil contamination and the suspect damp spark plug), crack in the block somewhere (not likely but you never know...) Rear freeze plug is probably rotten. Are you getting pressurisation like from the freeze plug anywhere else in the engine like from the radiator cap? I would doubt the exhaust gas pressure would be enough to blow out a freeze plug but I think this engine is toast. Only way to know is pull it down and take peek at it's innards. If you know anything about the 4G64 the one thing that seems to consistently die is the ECM. Usually bad capacitors on the circuit board. Easy enough to remedy as long as the board hasn't been damaged by the caps leaking. Would you even able to legally swap the injection onto your G63B in CA? If you can find a running 4G64 and you can get this truck cheap enough, it might be worth it as a side project.