When looking at front of mini, under the bumper there are two holes . early minis were a direct bolt to subframe. Later ones some sort of tear drop isolator.These have to be disconnected. The there are the two tower bolts, up by the wiper motor and other side. They have to come out. There are two connections behind subframe. They may have to be loosen depending how low you wanna go. I would loosen the bolts.

Looks like I have to check my subby to see if any cracks have developed. I didn't know it was a common issue.

Thanks everyone, I thought once a frame cracked like that, I was pretty screwed. I would much rather just weld it back together, and will definitely reinforce it with a nice steel plate. It is definitely going to be a PITA to weld, right behind the body. I pulled the grill and bumper off, which accomplished essentially nothing.

I'll have to see what I can do about dropping the frame like bitz suggested. Does that mean unbolting the whole body to raise it (thus lowering the frame)?

My wife and I have done some autocross in it, so I would count that as spirited use. Plan to continue to race also, so definitely stronger is better.

Like Alex said above, it's not uncommon.

I had it happen on my 95 SPI.  I unbolted and dropped the frame down slightly to run a bead of weld around and also stitched a plate on.

With that separation of 1/8 thick steel, I would be looking at the bulkhead bracket on the right hand side to see if that separated as well.

To answer your question... about the circa 86 subframe, it should work. My Mini, a mid 1980's originally with a 998 got a 1275 high compression transplant by a previous owner. They bodged a few things (intake and exhaust off the 998) but the subframe apparently posed no problem and they did not change it. If they are both manual transmission subframes, it should not be an issue.

Not an uncommon failure on later cars that have seen 'spirited' use.

Weld it up and reinforce with a plate.

I was going to make a JBweld or duct tape joke, but anyways. 
I would vote VTEC swap,...being that you brought it up. 

I've never seen that before.

There's no reason why you can't weld that up.

Hi folks. My 93 mini recently decided that it hated me, and the front frame broke. This is right where the engine stabilizing bar mounts. I have a spare 998 front clip from a guy who was doing a VTEC swap, and could theoretically strip that out and mount it up...
I think it was an '86 RHD, but I'm unsure if that's the right move.
Options: Strip off 998 frame and try to put under my newer 1275?
Buy new front frame from here
Buy mini-tec chasis and get mo powa! (wife may not agree with this idea)

Thoughts? Opinions, especially on the 998 frame?
Thanks in advance!