Hi-po exhaust manifolds

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70Duster340

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Can anyone help me with something? I have the service manual on CD for the 1970 Duster, and have been searching it for info on torque specs for the manifolds. It only shows the passenger side manifold. I not only need the torque specs, but some photos of both sides would be very helpful.
Does the driver's side manifold have any sleeve nuts? It's been so long I can't remember.
Thanks
 
Thanks folks. Are these all nuts, or are some of the fasteners bolts? The service manual has some being nuts on both ends, but bolts on the middle exhaust runners. It also shows the cupped washers only on the front and rear of the manifold, at least the passenger side is what is shown.
 
Studs on the ends, hence the nuts. Bolts in between. 65'
 
Gotcha. So now I have to find bolts that will fit. What about the driver's side? All bolts? Can anyone advise what size I need to look for?
 
The studs on the ends (drivers and Passenger)are into the water jacket (it's why they use studs there) be sure to seal the studs when you install them.

They sell a new set of all the correct bolts, studs, washers you need for both sides...
 
Yeah, I already have all the studs and sleeve nuts. I was trying to save some money by just replacing just what I needed. I guess I will be better off just buying all new hardware.
 
70Duster340 said:
Yeah, I already have all the studs and sleeve nuts. I was trying to save some money by just replacing just what I needed. I guess I will be better off just buying all new hardware.
Click to expand...
Just measure the depths of the holes and buy 5/16 course bolts of the appropriate length. Don't forget the cone washers. Save where we can!
 
They are that hot, they screw into the head which is water cooled.
 
I believe they are 5/16-18.
The end studs are 5/16-18 head side and 5/16-24 manifold side.
 
Make sure to put sealer on the studs before installing so no coolant leak
 
Do you still need pictures? Cause my '69 340 has the manifolds bolted to it with reproduction hardware. But its under a table with blankets and plastic piled on it but I can get pictures if they still needed.
 
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Closest I could find from existing photos... this is one of the reproduction bolt/nut/washer kits and was identical to the 50 year old bolts that came out. By the way the cone washers are to change the pressure of the nuts and bolts on the fragile cast iron "ears" where the manifold mounts to the head. Pressure in the middle would split the cast iron, where pressure around the edge tend to press the cast iron together
 
str12-340 said:
View attachment 1716226586

View attachment 1716226587
Closest I could find from existing photos... this is one of the reproduction bolt/nut/washer kits and was identical to the 50 year old bolts that came out. By the way the cone washers are to change the pressure of the nuts and bolts on the fragile cast iron "ears" where the manifold mounts to the head. Pressure in the middle would split the cast iron, where pressure around the edge tend to press the cast iron together
Click to expand...
According to my service manual, the conical washers are placed on the studs on the #2 and #8 exhaust ports, but none on the #4 and #6 ports. Unfortunately, it only speaks of the passenger side. It only mentions the torque specs for the driver's side. No mention of the conical washers for the driver's side. Would it be safe to say that those washers would be on the #1 and #7 cylinder ports?
 
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