ok just looked up the post BTW his motor came outta a FWD car

I have yet to chat with that guy, but...

I would start cutting away at the firewall long before I would consider doing anything with the rocker covers. I don't think exhaust will be a problem stateside as it's virtually identical to GenI design. I'm hoping that the 3.0L oil pan will fit on the 3.5L, but I don't have any measurements on that yet. A huge wiring task is to be expected. The fact that the guy mentions that it took a good mechanic to get it working makes me wonder if he had anything to do with the transplant, or if it was just handed over to someone to "make it happen"?

What we really need is for someone to import the hacked front and rear clips from JDM SWBs...

I seem to remember the 3.5L oil pan being a rear sump just like the SWB 3.0L. May not need to mess with the oiling system at all as long as the donor 3.5L comes from a montero.

Motor mounts will be fairly easy, but the extra width of the DOHC heads might be the hard part. I wonder how much narrower the SOHC 3.5L is than the DOHC version?

I have 3.5L SOHC in "Her Truck" and can measure whatever anyone wants...

Here's my take on the 3.0 to 3.5 swap. The 3.0 & 3.5 blocks are very close. The 3.5 block is slightly wider and has a higher deck height. I know on the Gen II's, a different bracket between the motor mounts and the frame is the only difference between the 3.0 Gen II's and the 3.5's. I also know that the flex plate from a 3.0 will bolt up to the crank and also the transmission will too. At least this is what I've gathered from the 3SI guys who do the 3.0 to 3.5 swap. Here's a link with lot's of information on a 6G72 to 6G74 swap.

I think the easiest would be to use just the 3.5 short block and bolt on the 3.0 heads. They are interchangeable. Also, reuse as much of the stock accessory brackets (keeping the stock locations) as possible. I would look in to using the timing belts and covers from a SOHC 3.5, plus the lower intake plenum. I'm guessing the upper 3.0 plenum will bolt on, but haven't confirmed this. Also, by using the stock heads, you can keep the stock ignition system. Fuel injection might require higher flow injectors, but otherwise I think it would compensate for the greater air flow.

If I was to do this, I'd start with a 3.5 SOHC rebuildable core. Rebuild the short block, then set the two motors up side by side and start mixing & matching parts. I'm sure there are small details that would have to be worked out but bet it's all doable without too much effort. You won't get the same power output as a stock 3.5 but I'm guessing it will be better than either the stock 3.0 or even the 24 valve SOHC 3.0.

My first reaction to all that is that the difference between the 3.5 SOHC and the 3.0 24V is what, about 25HP? That sounds like a lot of work for an improvement of what, 15-20 HP. In which case, it seems to me to be like the turbo swap. That is, if you have to rebuild the motor, and if you can get a swap donor for the right price, then yes go for it, as the incremental costs for the swap itself over the inherent costs of the rebuild are not significant.

Of course I'm talking about myself in the end as I have the 3.0 24V. If we're talking swapping with a 3.0 12V, and even a Gen I to boot, then that may different. Even so, a 3.0 24V swapped into a Gen I would be an improvement that likely wouldn't be that difficult (?).