78 II which 302 exhaust manifolds

Texas275

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May 31, 2024
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I have a set of the Mustang II Headman Headers but they will not fit with the 84 RUG transmission I have. Starter and clutch lever in the wrong place.

Can someone give me the part numbers off of the stock 302 exhaust manifolds that came in these Mustangs? I’m looking for a set and there are a lot of 302 manifolds for sale. Unfortunately I’m really not sure which ones I need to be looking for.

Thanks, Tom
 
They're hard to find pieces. I don't have any part numbers or anything, but they are specific to the car. Maybe @2Blue2 @Enzio or @extra_stout can help.


I'll apologize in advance if you're already aware of everything I'm about to share, but something else about V8 swaps is that the frame mounts are specific as are the oil pans. I've posted the oil pan part numbers in the oil pan gasket thread I posted, it's in the tech sticky at the top of the page. The motor mounts are pretty easily obtained, I believe Classic Auto Reproduction offer them, but the frame mounts are usually tough to come by. And the transmission tunnel is pretty narrow, but a lot of times it's nothing a BFH can't take care of. It's just something to keep in mind when running your exhaust. Everything else is pretty straight forward, but those are usually the biggest obstacles.
 
Here's the oil pan thread I referenced in case you need an oil pan.

 
Thanks for the response. I have been collecting parts and reading everything I can find to do this V8 swap for months. I got an oil pan from Classic Industries that fits the II. I bought the motor mounts and the headers off of Facebook market. As well as the transmission. I put it all in and it fit like it should except for the headers. That’s why I’m looking for the stock manifolds.

I have found several on eBay, but they all are not the same. That’s why I’m hoping someone can give me some part numbers. Heck even some pictures of what they should look like will help.

Heee is where I got the oil pan if any one is looking for one. I got the chrome one only because it was 10 bucks cheaper than the painted one.

 
Fwiw, I don't think any of the II headers were designed for a 4 speed car. I have the old Black Jack headers which are arguably the best fitting with a stock II bellhousing and clutch assembly and I had to massage the headers to make them fit. There was a boss on the bell that interfered and the clutch fork cover would NOT fit regardless. I had to partially flatten the tube just for the clutch fork to operate. If the clutch fork is clocked into a higher position, that will just close the tunnel even more and most likely interfere with any set of headers worse than what I have. Running stock manifolds might work if you run the exhaust below the fork, but then you may run into problems with the clutch cable. :shrug:

I guess what I'm alluding to is you may need a II bellhousing, flywheel, and clutch too. Both I and @Enzio run T5 transmissions now. The difference between he and I is that he had a hydraulic clutch system retrofitted whereas I still run a cable. So if the fork and/or cable is the main issue, you may be able to go down that path. Like I said, finding stock exhaust manifolds will most likely be a challenge. One person that I can think of that may have a pair would be Phil Schmidt. Someone here might, but I don't have any of his info. You may find him either on Facebook or just a Google search though. I'd say he's probably your best bet with finding them.
 
I believe I could work around the clutch fork and cable position on the left side. Starter position wont allow the right side to work at all.

My motor is out of a 1970 Mustang so it has the smaller flywheel and clutch. I was looking for manifolds as the RUG is direct bolt in without having to modify anything else on the transmission. I don't know what I would have to change to use a II bellhousing. I found a write up on the old mustangII.org site where a RUG/SROD was put into a II with stock exhaust, and he didn't have to alter the the exhaust.

There are several different manifolds for sale especially on ebay that say they fit, but they are all a little different. That's why I was hoping someone would have a part number or a picture of the proper manifolds.
 
There are several different manifolds for sale especially on ebay that say they fit, but they are all a little different. That's why I was hoping someone would have a part number or a picture of the proper manifolds.
You mean used manifolds or shorty headers on ebay?
The only new manufactured manifold that works is the 66 mustang manifold. This is what i'm using...
Don't have a part number of the original manifold.
 
I used stock 66 Mustang exhaust manifolds because I had them already from a previous car (they are available as new part). I also used a 66 mustang downpipe from pypes and modified them:

The manifolds fit even with a T5 bellhousing and T5 transmission (but with custom hydraulic clutch). The car pulls strong, but its for sure restrictive at high RPM compared to a shorty header.
What I like is that you can use the stock securing sheet metal from the 66 manifolds, so the exhaust manifold bolts don't come loose. Beside that they are durable and quite down surface radiated noise in the engine compartment.

I have a stock 2001 explorer 5.0 as basis. If i would step up from the stock cam, i would buy or build shorty headers or log manifolds.

One shorty header that could work is this one (because it is made specific for 66 mustang):
I live oversees... so I have no option to return them if they do not convince me with their fitment...
 
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and here the sheet metal parts with the locking tabs for the exhaust manifold bolts:
 
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Starter position wont allow the right side to work at all.
How is this even possible?
The starter position is the same for every SBF ever made.
If the starter is in the way of the headers, then those headers will not fit any SBF.
Or, you could try with a mini starter like used on 94" up 5.0's
If it won't clear that, then the headers are defective from the manufacturer.
 
I have a set of the Mustang II Headman Headers but they will not fit with the 84 RUG transmission I have. Starter and clutch lever in the wrong place.

Can someone give me the part numbers off of the stock 302 exhaust manifolds that came in these Mustangs? I’m looking for a set and there are a lot of 302 manifolds for sale. Unfortunately I’m really not sure which ones I need to be looking for.

Thanks, Tom
Here are the part numbers for the stock manifolds:

V8 exhaust manifolds.webp
 
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How is this even possible?
The starter position is the same for every SBF ever made.
If the starter is in the way of the headers, then those headers will not fit any SBF.
Or, you could try with a mini starter like used on 94" up 5.0's
If it won't clear that, then the headers are defective from the manufacturer.
The Mustang II C4 bellhousing is specific. Also the oil pan. I could also imagine that the bellhousing of the RUG transmission is Mustang II specific.
It's a very special car :cool:
 
The Mustang II C4 bellhousing is specific. Also the oil pan. I could also imagine that the bellhousing of the RUG transmission is Mustang II specific.
It's a very special car :cool:
The block dimensions is exactly the same.
The bellhousing bolt pattern is exactly the same.
Are you saying that the C4 bellhousing for the Mustang II is larger in Diameter than a C4 bellhousing for any other SBF?
That is the only explanation.'The starter would have to moved further away from the block in order for it to be an interference to the header tubes.
Therefore, it that is the case, get a normal C4 bellhousing and matching flexplate and problem is solved.
The starter will now be closer to the block and header clearance should be fixed.
 
My understanding is the II bell housing is small and has the starter sitting in a somewhat different position on the bell housing. The headers are designed for the II bell. Not an 84 4 speed. Trans was not with the car when I got my hands on it, so I have no II bell housing.
 
The block dimensions is exactly the same.
The bellhousing bolt pattern is exactly the same.
Are you saying that the C4 bellhousing for the Mustang II is larger in Diameter than a C4 bellhousing for any other SBF?
That is the only explanation.'The starter would have to moved further away from the block in order for it to be an interference to the header tubes.
Therefore, it that is the case, get a normal C4 bellhousing and matching flexplate and problem is solved.
The starter will now be closer to the block and header clearance should be fixed.

The II flywheel is a smaller diameter than any other small block. That necessitated that the starter be moved inboard a little. So II headers are specific to the car because they had to hug the engine/transmission combo tightly due to the smaller transmission tunnel that IIs were designed with. The reason for the small tunnel was that the II was never designed with a V8 in mind, which is why when it was introduced in 74 the only engine options were the 4 cylinder or the 2.8l V6. When they added the V8 for 75, they had to design the bellhousing to fit the tunnel. They also had to redesign the upper section of the radiator support to move the radiator forward, which is why the 74s have a deeper nose vs the 75-78 cars.

74:

1731792845728.webp



75+:

1731792892439.webp