318 with PS.....What manifolds will fit?

[serodgers66]

Evening everybody. I have a 65 Valiant with a 318 (302 heads) and stock power steering. I removed my Doug’s headers as the constant leaks and rattles and decibel level were starting to wear on me and decided to switch over to manifolds. I picked up a pair of 5.9L Magnum manifolds from a 1997 Dodge on the cheap. I now realize that the passenger side will fit but the driver’s side will interfere with the PS. After late nights of google research I am not clear on what my options are. Looks like 73 340 manifolds are the holy grail but require serious $$ (even for just the right side) and I have seen conflicting reports on whether they will even work with PS or not. I’ve read about switching to manual PS or installing a Borgensen box. If early manifolds will work, what specific year? I assume mixing an early manifold on the left and a magnum on the right isn’t a good idea. I don’t really care about the power aspect…this car is just a cruiser. The rumble and aroma is all the pleasure I need. Oh yeah, exhaust is 2 1/4" X-pipe. I thank everyone in advance for their help!

 

[Professor Fate]

The only thing that will fit with factory power steering (no idea about the Borgeson unit) is the early A 273 manifold, '64-'66.
With the 302 heads (or any later model head with the large exhaust port flange, smog era) you will have interference with the manifold's down leg and the #7 exhaust port. This normally will require you to run a header flange as a spacer between the head and manifold (driver's side only), although some have reported to have gained sufficient clearance with double gaskets. Don't grind the head unless you feel really lucky- there's a coolant passage just under the surface in the area that you'd grind.

There is no port mismatch since the 318 and 273 have the same size ports. No issue running a 273 D.S. and Magnum P.S. manifold if you so choose.

 

[65 Dartman]

This might not be your cup of tea, but you might consider a stock Commando single exhaust with the resonator Uses stock 65 manifolds and will give you the sound you want

 

[serodgers66]

The only thing that will fit with factory power steering (no idea about the Borgeson unit) is the early A 273 manifold, '64-'66.
With the 302 heads (or any later model head with the large exhaust port flange, smog era) you will have interference with the manifold's down leg and the #7 exhaust port. This normally will require you to run a header flange as a spacer between the head and manifold (driver's side only), although some have reported to have gained sufficient clearance with double gaskets. Don't grind the head unless you feel really lucky- there's a coolant passage just under the surface in the area that you'd grind.
View attachment 1716386620
There is no port mismatch since the 318 and 273 have the same size ports. No issue running a 273 D.S. and Magnum P.S. manifold if you so choose.

So this manifold will work with the header flange? Certainly looks shaped the right way.

 

[serodgers66]

This might not be your cup of tea, but you might consider a stock Commando single exhaust with the resonator Uses stock 65 manifolds and will give you the sound you want

thanks for the suggestion. If the whole exhaust system was shot, I'd consider this route but the rest of the dual exhaust is in great shape. I actually just replaced the mufflers with dynomax super turbos to try and quiet it down (didn't make much difference at all). So I'll be sticking with the dual exhaust for the time being.

 

[Professor Fate]

So this manifold will work with the header flange? Certainly looks shaped the right way.

That's the one, although that one's priced a little high, in my opinion.
If possible, get one that comes with the support braces- commonly missing. Not absolutely necessary, but Ma Mopar put them on there for a reason. They can be fabbed pretty easily out of 1/2" EMT if necessary.

 

[RAT ROD AL]

I just pulled one off my 64 parts car . I'll check it over and let you know if it's good !

 

[Syleng1]

In my 66’ Barracuda I have Doug’s and factory Power steering. I switched to Borgeson power steering box and it solved a lot of issues. Mostly clearance.
I’m running dual 2-1/2” tti x pipe system. It’s not loud at all.
Headers to work properly are a bunch of fitting work. I’m also not driving my car daily. (500miles last year)
Early abodies are tough since they really are so tight with a v8.

 

[serodgers66]

So I settled on the 64-66 manifold plus 3/8” header flange for the drivers side and the 97 magnum manifold for the passenger side. What is the best way to source manifold studs? I have quite a few different lengths that I need now. Can I just get some 5/16 x 18 coarse threaded rod and cut them to length and crank them down with double nuts? Buy a generic kit? Is there something specific that I haven't come across? I appreciate the help!!

 

[Professor Fate]

So I settled on the 64-66 manifold plus 3/8” header flange for the drivers side and the 97 magnum manifold for the passenger side. What is the best way to source manifold studs? I have quite a few different lengths that I need now. Can I just get some 5/16 x 18 coarse threaded rod and cut them to length and crank them down with double nuts? Buy a generic kit? Is there something specific that I haven't come across? I appreciate the help!!

Just go to the parts store or a well stocked hardware store for the studs. For the driver's side, 3/8 longer than stock will get you there (studs are only used in the two end positions of the head), all you need to do is make up for the additional thickness of the header flange. If I remember correctly, I used 5/16x 1 1/2 automotive studs.
On the passenger side, a Magnum manifold does not use any studs, and if you did they would be so long that there'd be no way on earth you could ever pull the manifold off for any kind of service with the very limited amount of clearance between the manifold and inner fender, which would mean that you couldn't pull the head (for instance if you ever had to replace a head gasket), which means any kind of work on that side would require pulling the engine...
The stock manifold didn't have that issue because of it's relatively thin flange that in turn uses a shorter stud. The Magnum manifold's "flange" is probably close to two inches thick on the ends, so you'd need a three inch stud- and that adds up to four and a half to five inches of clearance you'd need in order to remove the manifold.
Long story short, just use bolts on the Magnum manifold, and sealer on the two end bolts.
And no, don't use All-Thread rod for this! It WILL snap, and then you've got to deal with drilling out the hole- not fun.
Studs are hardened and can take the tension from heat/cool cycles. And you only need two.

 

[serodgers66]

10/4. I'll order the kit for the magnum and get 1 1/2" studs for the driver's side. Appreciate the advice!