Replacement manifold doesn't match mine (Ford 4.6 SOHC experts needed)

So I have a 2001 GT that has had its heater hose nipple cracked, and I went to buy this replacement intake manifold (used, said it came off of a New Edge car) but doesn't match up with mine. I did have my car's engine replaced a while back with an '04.

Can someone tell me if I do have a 2004 GT 2V engine, or is from another car? What intake manifold do I have, and which car did the replacement come from? For reference, the one that's cracked is the one with no shiny and reflective sealant:

https://i.imgur.com/CpQsiEH.jpg

https://i.imgur.com/O8JZ8W0.jpg

https://i.imgur.com/i9w5lmQ.jpg

https://i.imgur.com/zdjAikE.jpg

https://i.imgur.com/GfnZ8ng.jpg

P.S. Another issue - my dad broke and stripped the radiator drain plug cap. Suggestions on how to get it out? In the meantime, is there another hose I can open up to do a coolant flush? He also got oil in there :(

Speaking of which, how does one make sure an oil+coolant mix is completely gone from the radiator system? Car hasn't started yet, was planning on just using a normal flush mixture or a water+dishwasher soap combo.

Ford made the 4.6 in two factories, one at the Romeo plant in Romeo, MI and the Windsor plant in Windsor, Ontario. There are differences between the two, but the only noticeable external difference between the two is the number of bolts holding down the valve covers (one has 11, the other 13). I don't recall there being a difference in the exhaust manifolds though (It's been awhile since I spoke Ford modular motors). I do know that they switched to the PI (performance improved) heads around 1999, so it's possible that you may have gotten a manifold from a non PI engine. With regards to the radiator problems, other members of the hive here will have a answer.

I misread your post and thought you said exhaust rather than intake. I don't recall there being any difference in intakes between the two motors either. I know Ford redesigned the intake in the early 2000's because of the crosstube cracking and leaking (that's why I replaced mine on my 03 GT). Yours appears to be missing the aluminum crosstube and thermostat housing at the front of the intake.  It's possible that you got one for an earlier non PI motor, but I can't really tell from your pics.

The intake port shape is the big difference on the heads, i wonder if you could have ended up with a panther platform intake?  I think i threw out my last one so i can’t just go look in the garage

Your pics make it hard to tell what you have, but there are two main flavors of 4.6 2V car intakes, the NPI (non-Power Improved) that came on all 96-98 Ford/Lincoln/Mercury passenger cars with the 4.6, along with 99-mid 01 Panthers), and the PI (Power Improved) intake that came on 99-04 Mustangs and 01-up Panthers.

Below, the PI intake is on the left and the NPI on the right. The easiest way to visually spot the difference is that on the PI intake, the frontmost runner goes to the driver side head. On the NPI, the frontmost runner goes to the passenger side head.

The PI intake also has much longer runners than the NPI intake, so if you lay them side by side, the PI will be taller.

The intake in your pic also has the early plastic coolant crossover. It's a huge failure point, so Ford designed new NPI and PI intakes with aluminum crossovers and replaced a ton of each under warranty.

I can't tell which manifold is which, can you post a full top view of the new one you bought?

There is also a Dorman aftermarket intake for the PI 2V. It's cheaper, but supposedly you lose HP up top. It also looks different than a stock Ford 2V intake. All the new Ford ones have the aluminum crossover.

The one you're posting pictures of is missing the aluminum crossover pipe, as was mentioned earlier. I have one with a plastic crossover sitting in my basement, if you need pictures for reference. Where are you located? I would give you my old one, provided you check for cracks in the  crossover (I couldn't find any - I came to the conclusion that my coolant leaks were because the intake manifold gasket was shot).

In terms of the radiator drain plug, I broke mine as well but was able to remove it. Look at what's left of the plug, there may be a recess that will fit an Allen key.

So I had my parts checked out - the one with the orange gaskets is the Dorman trash variant

Had that tossed, but am having a different dilemma (took care of the oil in radiator dilemma, thanks to your guys' advice):

The aluminum crossover I got seemingly has the hole for the coolant temperature sensor blocked off. Any suggestions as to why the previous owner would do this?

https://i.imgur.com/2qdiOH8.jpg

No, that's weird. Look at the first pic I posted earlier. The NPI intake has two coolant temp sensor locations in the crossover. The PI intake only has one (passenger side). Your pic shows that bung isn't drilled or tapped. To me that looks like lousy QC, assuming it's a new piece. 

Looks like the PI is on the bottom in this photo going by the longer runners making it taller.