Correct OEM Manifold Gasket? 3FE Exhaust Manifolds/F Engine Intake Manifold/'76 2F Engine

[4Cruisers]

For my '71 FJ40 build I plan on using the low-mileage 2F from my '76 FJ40, with 3FE exhaust manifolds and an F engine intake manifold. I want to use an OEM gasket but want to make sure I order the best fit for that combination. Any input would be appreciated.

I'll have the machine shop that rebuilt the 3FE in my '86 FJ60 mill the manifolds as a set, including getting the flanges to the same thickness. Is it as critical as when you match a one-piece exhaust manifold to an intake manifold?

 

[4Cruisers]

Here's what they look like together:

Next I'll take a look at the 2F cylinder heads - there's one each installed in my two FJ40s. I'll check the studs/bolt holes.

 

[4Cruisers]

I've searched for quite a while now and can't find a photo of the manifold side of an early 2F 61030 cylinder head. I'd like to see what the manifold studs and manifold bolt holes look like so I know what I'm dealing with. Does anyone have a photo they can post? Thanks.

 

[4Cruisers]

I'm starting to think the 3FE exhaust manifolds won't be compatible with the '76 2F cylinder heads. Can anyone confirm?

 

[4Cruisers]

I searched some more, and found a photo in my Toyota 2F Engine Repair Manual. I believe this is what the cylinder head on both of my '76 2Fs looks like:

The six manifold studs on the cylinder head will secure the intake manifold properly, and will secure the 3FE exhaust manifold in six spots - one exterior ear of each half and two interior ears of each half. Not sure if that'll be enough even using an OEM manifold gasket.

And for sure, a 3FE gasket will not work:

 

[4Cruisers]

I think I found the answer. An FJ60 2F manifold gasket like this:

I

I just went out to take a look and sure enough, there are threaded holes in the '76 2F cylinder head at Positions #7 and #8. I didn't realize that earlier. That means I can secure the 3FE exhaust manifolds at those locations also, for a total of four on each section. So I'm good to go, right?

 

[4Cruisers]

I pulled a couple of bolts from my stash (91611-61028) that are the specified bolts for those two locations, threaded one in the front hole until it bottomed, and measured the remaining gap between the washer and head. Then I measured the thickness of the 3FE manifold (15mm) and added some for the thickness of the OEM manifold gasket. Looks like I'm good there.

Then I removed the nut from one of the manifold studs in the '76 head and discovered it's a 10mm stud. And the holes in my spare intake manifold, the one I'll be using with the 3FE exhaust manifolds, are sized to fit the 10mm studs. The intake manifold is only 10mm thick, so I'll plan of fabricating some stepped plate washers for the six locations where the manifolds share a stud.

 

[4Cruisers]

After a lot more research and studying here's what I plan on doing.

F intake manifold (with F engine 2-bbl. carburetor), 3FE exhaust manifolds, Fel-Pro MS 22813 manifold gasket (for '76 2F), FJ62 manifold hardware (two bolts 90119-10038, six stud bolts 90116-12011, six washers 90201-12004, and six nuts 90170-12211), and six custom 5mm thick half washers to make up the difference in thicknesses of the F intake manifold and 3FE exhaust manifolds (two stacked thick hardened washers each 2.5mm thick).

My initial thoughts were to use only two stud bolts and replace the other four stud bolts with four 3FE bolts 90119-12069 as recommended by @FJ40Jim in another post, but those bolts are NLA.

 

[WaTrout88]

How did this turn out? What was the reason for using a F vs the 2F intake? I am looking into doing the same and replacing my aging header.

Thanks
Ben

 

[4Cruisers]

How did this turn out? What was the reason for using a F vs the 2F intake? I am looking into doing the same and replacing my aging header.

Thanks
Ben

That's what came with the FJ40 when I bought it over 20 years ago.

 

[Dizzy]

The ebay F intake manifold that I have received galling from someone skipping a washer or something, so the 'counter bored' or 'spot faced' machined surface will not measure a consistent surface. I hope that readers will respect these tabs on their own manifolds, and not install nuts without a smooth steel washer against the aluminum tabs. Just a bump in the road to look out for.

The F studs are smaller by a millimeter or two on diameter. The half circles in the F intake tabs reflect that. Use the stepped stud (F accessories on a 2F head), unless the intake will clear without conflict. Also, the washers (special Hillman) for my 2F equipment don't fit in the 'counter bore' or 'spot face' on the F intake. I'd have to do a little washer grinding, or get a shop to mod the F intake. I guess I could file the intake for the larger 2F stud's diameter, but a larger diameter 'spot face' or 'counter bore' would bring it up to speed with the specs on a 2F intake. BTW, if you need an uncracked, beater intake from a '71, take mine - better modifying mine, then modifying a pristine original if it has to go under the mill or whatever.

Personally, I wouldn't try to modify washers. Rather, standoffs. Use a short section of tube, and mill off half a centimeter for the later exhaust manifold. The reason is, one-piece vs two makes for ease of installation, plus, it allows you to use a longer stud/bolt (I'd stick with Grade 8.8, without knowing better, if using generic). Longer fasteners 'stretch' more, which is going to allow for more fastener tension with the same amount of fastener torque. However, welding a stack of half circle washers together with a full washer, might be a satisfactory solution as well.