So, I just picked up a T100 with a 3.4L engine for parts (was locked up/rusted a bit in the cyl). Anyway, it looks like the cross over pipe might be a close match on the 3.0L if the 3.0L had two passenger side manifolds installed. I don't have the engines side by side so I haven't looked it over that well, but figured I'd put it out there to see if anyone has tried similar?

Of course the end goal is to prevent the #6 cyl heat and head gasket problem. I have a 4runner with the 3.0L I just bought for $250 with the #6 head gasket problem, so researching options before I start dumping money into it. Rusty body but ironically the frame isn't bad for Michigan. Figured it will make a good winter beater to keep my 96 Tacoma in better shape.

Ideas, Experience?

BTW, I'm doing the work myself and on the cheap, since the 4runner isn't worth much more with a good running engine. Aka $500+ headers are a no go for me.

 

Are the exhausts not on different sides ?

Now the T100 being the odd ball I can`t recall if the exhaust is on the right and fuel tank on the left like the Tacoma`s and Tundra`s

I know the older 3.0 vehicles the exhaust is on the left and fuel on the right.

being the reason one rebuilds the cross over pipe when doing the 3.4 swap

 

Pretty positive the T100 exhaust is on the passenger side like the Tacoma's. Didn't really think of that till a few hours after I posted this. Anyway, chop saw and a welder, seems like it wouldn't be too hard to swap the side the down pipe goes on, just not sure if the flange is the same bolt pattern. I have a 3.0L to mock up the cross over pipe on when the time comes. Also found out there is an "old" and "new" style manifolds for the 3.4L with the turnover date in 2000. Mine is the old style of course (2000 and older).

I guess worst case, I could hack up a 3.0L cross over pipe for the flanges. Other option being the trickier exhaust run.

The cat back is pretty toast on the 4runner so I'd probably be parting together exhausts from other trucks/cars in my yard with good ones, or patching up the odd holes in the cat and exhaust. Guy I bought it from claimed to have "rebuilt" the mass air flow meter twice and told me that isn't the problem. He added grounds and I'm guessing poked the holes in the exhaust to check if the cat was plugged. Anyway another mass air flow meter made it run lol.

 

I just did this on my 95 4runner.
I picked up a crossover from the junkyard and used those flanges. I also bought a flex pipe and welded that first onto the pass. side flange. down tube and an exhaust 90* to a small straight run, then to a 45 into the existing exhaust. I also bent some sheet metal I had to wrap around the down pipe, and left about 1/4" or so between them. So it became a double wall. Then I wrapped the whole thing with some header wrap. Just make sure you have enough space between the "new" exhaust and all the brake and fuel lines on the pass. side as well as enough gap between the exhaust and the trans pan so you don't heat up the trans fluid.

 

Just to make sure I'm thinking right, the 3.4L flanges fit on your 3.0L flanges right? That and you used two passenger side manifolds? Have any photos by chance? I know running the exhaust down the passenger side is tricky but not impossible since the T100 must do the same thing with the older style layout.