I'm making this as a bit of a guide, seeing as how there is a lot of information out there, but none of it is really condensed.

First, the basics. I have a 1989 LWB 6g72 5 speed montero. The original engine developed a condition where it no longer had spark on cylinder 2. nothing fixed it. new plugs, wires, distributor, computer, cap, rotor.... NOTHING. then came the rod knock. Time to go. Finding another montero 6g72 around here is nigh impossible. so, when a 6g74 out of a 2001 showed up in a local u pull it, I jumped on it.

Preliminary and crude measurements indicated that the transmission bolt patterns are the same as well as the flywheel bolt patterns. More accurate measurements with both engines out of the car confirmed it. I'll be using the stock clutch, stock 6g72 flywheel and clutch as well as the stock 6g72 starter. A few major hurdles down.

The 6g72 motor mounts and isolators will bolt on to the 6g74 block and clear accessories and exhaust manifolds. Some of the holes will need to be drilled to accommodate larger bolts and some of the holes will need washers between the block and the mounts. pain in the ass level 2. tops.

drivers side.. all holes line up, but a few need to be made bigger.


more driver side... you can see that with one mount hole flush against the block, others will need spacers





passengers side. same thing. all holes line up, some need to be made bigger.




The oil pan..... The lower portion of the 6g74 oil pan will have to be cut and re-welded to clear the front axle in the 89 monty. The cut should not interfere with the pick up and the only welding that needs to be done is on the lower steel oil pan. the aluminum upper portion should be just fine the way it is. pita lvl 3, maybe 4.

heres a shot of the oil pick up. excuse the messy garage in the background...


and that yellow line is where the oil pan will have to be cut and welded, the red line is where the edge of the pick up would be inside the lower pan.



The exhaust.... it appears as though the stock drivers side exhaust manifold will match up with the factory gen 1 system. The passengers side is a different story and may require a custom piece to connect to the rest of the stock exhaust system. pita lvl 4. tops.

The alternator.... being controlled by the computer is kind of dumb. I'm thinking of just wiring in an external voltage regulator. like something off of a ford. yeah, I know ford parts yuck. but, cheap and easy! pita lvl 1

The engine management... I'm just going to go megasquirt here. Ive done it on a few other cars, and I am fairly confident I can make it work on a 6g74. I plan on using MSII and using the stock crank + cam position sensors with MSII firing the stock wasted spark coil packs. I'm going to gut a spare ECU and use the connector and run it to the DB37 so I can still use the stock wiring harness for the majority of the install. I am planning on running a MAF with this so as to sidestep the majority of tuning headaches associated with a MAP set up.

I'll update this the further I get in the coming week or 2. I hope to have it running by thanksgiving.

Lot of thought into. Looking forward to progress reports.

ran into some problems. Rotten crank angle sensor cracked in half when I put it back on, new part ordered. Then, when installing the timing belt, I breathed wrong on the right side head and it spun, sending the valves into the top of the piston. I'm fairly certain I have bent valves as now I have almost no compression on one cylinder when cranking by hand. I guess the beast gets a valve job now too.

I have a question for anyone knowledgeable about the 6g74 SOHC engines.... So, I need a few valves. There is a local junk yard that has COMPLETE diamante cylinder heads for sale for $14.99, yet they are not listed as an interchange for the montero.

WHats the difference between a diamante cylinder head and a montero cylinder head? They both have 9:1 compression. they are both 6G74. Different cams?

My understanding is the cams are different, designed to run higher rpms.

I am bumping this up, was hoping there was an update

Zombie thread!

McAdam, looks like your 6G74 came out of a Montero Sport which would explain the oil pan clearance issues. It is as simple as swapping a Montero oil pan and pickup tube. I had to do that on my 6G74 swap ('04 Sport into '99 Montero) and we did no oil pan modifications to PA_JERO's 6G74 DOHC (from a Montero) swap into his '87 Montero.

Remember Montero Sport = Mighty Max = L200 = Triton and the compatibility between that chassis is great Gen 1-3 with the Montero Sport being the 3rd Generation of that group.

That's good info to have, since I've got a 1999 Sport 6G74 waiting to go into my 92 Mighty Max. It'd be nice not to have to mess with the oil pan.