The M60 fits very snugly into an E30 engine bay. Being DOHC, it is obviously bulkier than the LSx and leaves less room for all the other things.
The front sump of the RWD M60 fits perfectly around the RWD E30 crossmember.
The left cylinder head covers about three quarters of the stock hole where the vacuum booster mounts.
Simply converting to hydraulic brake boost is really not that hard. Quite a few 7's had hydroboosts. The E23 cars even had remote accumulators which make packaging even simpler. The Hydroboost conversion is pretty common M50 or S50 swapped E30's, as it leaves more room for the intake manifold.
The hard part of the brake setup for the M60 swap is that the entire linkage needs to be relocated.
See this thread for links to interesting ideas:
http://forums.bimmerforums.com/forum/sh ... ?t=1698125
The basis for most of the remote booster builds in the E30 is BMW's factory remote booster installation in V8 E34's. This uses a rocker arm to convert the push from the pedal into a pull which operates a pull rod, which pulls on another rocker arm which pushes on the remote booster. I purchased one of these setups that was already modified for use in an E30. I will probably end up using the E34 booster-end hardware with a custom pedal-end rocker arm similar to the fully custom LS1 swap linkage pictured in the above thread, but *inside* the firewall.
The brake linkage issue has been tackled in a couple of different ways and isn't that big a deal, IMO.
The steering linkage with the E53 V8 front diff looks like it'll take some thinking, however. Because the V8 sits "vertical" and the I6 is leaned over, the block skirt on the diff side of the I6 is higher. This means that the diff can tuck into the I6 much closer to the crankshaft centerline than it can with the V8. The diff sticks out the side of the pan more with the V8 and, as I'm finding out, interferes with more stuff. AND between the steering, diff, axle and driveshaft, a 2.5" exhaust pipe also has to find its way out.
The mid-sump of the AWD M60 *appears* to fit well around the AWD E30 crossmember, but I won't really know until I get the engine into the engine bay. I have a lot of measurements to take to convince myself that this will work before I drop $3-4K on a car.
And other than buying a harness, I haven't even touched the DME yet...
The big issue with the LS1 E30 swap appears to be the oil pan. The couple of swaps I've seen documented use a modified GTO oil pan. I can't help but think that the extreme rear sump configuration of the truck oil pan would work. That's a SWAG, though.
Because the Chevy bellhousing is large, it apparently doesn't fit all the way into the E30 trans tunnel. This means that the engine has to sit a couple of inches further forward of where it should be, which also means it has to be a little higher. I'm not sure if it could sit lower with the truck pan and go further back, or if modding the firewall to allow it to sit further back would then allow it to sit lower...
Anyway, for a number of reasons an M60 looks like a better swap into an E30 than an LSx.
However, the E36 crossmember configuration makes the M60 swap much harder, but the engine bay layout makes the LSx swap much easier. If you want an LSx powered BMW, start with an E36.
Edit: It looks like firewall mods to an E30 would be similar to firewall mods to a LSx Miata:
http://flyinmiata.com/V8/Newton/index.php?UID=
Edit again: Another similar build:
http://flyinmiata.com/projects/targa/Ta ... php?UID=31