This information may help with a M30b35 swap into other BMW platforms using the M30 engine. E12, maybe e28. I will address and provide as many photos as I can for each of the items I will list below
The reason I have selected to use a standalone engine management system (the www.classicdaily.net Turkey and Cheese) was to eliminate a few proprietary components that can be problematic or difficult to obtain. The Motronic DME can have issues with the circuit board after 30+ years of heat cycling. The Air Flow Meter (AFM) can be problematic and even rebuilt ones are expensive. The Throttle Position Sensor (TPS) is being replaced with an easier to find BMW M50 engine style. The Turkey and Cheese is compatible with the Motronic 1.3 55 pin engine harness and incorporates a wideband O2 sensor for better monitoring. I have also decided to use their coil over plug kit (using VAG R8 coil packs) to eliminate the distributor and central, single, ignition coil. With a lumpier camshaft, headers and a good fuel injection map, the b35 will produce significantly more power than the stock engine.
This project will also outline the retrofitting of a 5 speed Getrag Transmission. This has been more problematic than I anticipated.
COMPATIBILITY/ADAPTATION CONSIDERATIONS: ENGINE ONLY
Engine Mounts- later M30b35 blocks have different bolt boss locations. The exhaust side mount requires significant augmentation, The intake side probably does not but only 3 of 4 mounting holes line up so I did add a some material to the back of the mount to reduce potential flexing.
Throttle Actuation Assembly This was actually kind of fun to figure out but you will have to modify the pushrod set up for the carbs to work with the cable operated throttle body of the b35.
Cooling System I did not anticipate this being an issue but it is. Mostly due to the coolant hose routing.
Intake Modifications/AFM Delete
Accessories Do you want to use the 140a Alternator from the e34 (e32?) You will need to modify the mounting bracket from the donor engine if so, This was not straightforward but I will show what I did for this. Otherwise- you can use everything from your e3 and it will be easier.
Oil Pan/Oil Pump The oil Pan for the b35 will not work with the e3 subframe. The pan swap is easy- the oil pump took some figuring out.
Integrating Motronic 1.3 Wiring
Brake Booster The giant e3 brake booster will not allow for clearance for the b35 intake plenum (unless you cut/modify the plenum.)
Fuel System Additions A high pressure fuel pump and supply line will need to be installed.
Camshaft Choice This is especially important if you are going to go with a standalone engine management system. You will gain more power and torque with a more aggressive cam. I chose a 284 degree cam. The stock b35 cam is 264. Keeping the stock cam will make things a lot easier overall if you are fine with the stock setup.