I've done it in a CJ7, which is pretty much identical body wise to your YJ. Like Mach said, the biggest issues will be the front axle. I installed a lift to get the clearance, but the other option is to cut and splice the oil pan for more clearance. I left the transmission in the stock location so that I did not have to get new drive shafts.

I used all the existing ignition components, with the addition of the Mercedes glow plug harness. I ran the front half of the Mercedes vacuum line and ran it into the Jeep brake booster. I do not run a vacuum expansion tank but still have the motor turn off via vacuum when the key is off.

I am still fighting high temperatures when at speed above 55mph. I haven't had time to work on it in quite some time to figure it out. Power does seems to be lower than hoped, but I do think that some tuning adjustments would clear most of that up.

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'85 300D ~ 381k, HD Bilstien shocks, 27.50x8.50x14R General Grabber AT2 tires, 4 E-Code headlight upgrade with 90/130w bulbs, boost turned up, new timing chain, and injectors. SOLD

'85 CJ7 ~ OM617 swap, Tarus electric fan, T5 trans, Dana 300, 4.88 R&P, Mile Marker locking hubs, ALDA removed, AMC 20 rear disk brake conversion, Aussie locked with 33's and 5" Rough Country lift.