Pretty simple problem really, I've just got the Rebuilt A14 in the car and running but after putting coolant in (I went a round the block a couple of time with water only and flushed block a couple of times) and running around the block I have noticed the coolant is leaking out of the welsh plug.....on the back of the block >_<

I'm not sure if I installed it with a slight angle when I did it but it's held in with some aviation cement under instruction from some mechanic friends of mine.

Is this going to be an engine out job or could the gearbox be shuffled back enough to tap, ah screw it. Is it going to be an engine out job? >_<

Way easier with the engine out ;) u convinced ureself

Yep, engine out.

Fortunately it's not a particularly difficult job, but a damn pain if you just installed it.
Use a brass welch plug & put a brass one in the back of the cylinder head too.
What the hey, I personally use brass in all positions & will replace them in any engine that is out of the chassis & still has steel ones.
Brass never rusts.

That's the thing, I'm quite sure they were brass ones I put in. The put the rear one in first and I thought it was a little bit off angle but never thought any more of it after that.

I'm getting the extractors done today so I'll set all this up for the end of the week, user error plugs grrr.

If you put the head gasket on upside down(easy to do), this will cause a coolant leak at the back of the head also.

I wouldn't put that past me unfortunately. But here's some good news, while doing the exhaust today I checked the leak and it appears that it's related to system pressure so it must be tiny. When I initially noticed the leak the coolant temp was at 100c whereas today I kept it in check at roughly 80-85.