My son's 1975 Dart (225 Slant Six, auto trans) has a bad valve, and I wanted to install a Super Six setup that has been sitting around my garage for 20 years (that never made it into a '64 Valiant). Upon removal of the stock manifolds, the lower manifold bolts were so difficult to get to that instead, I removed the head and manifold as one unit. To do so I disconnected the rocker arms, alternator bracket, coolant lines, and exhaust pipe coupling, and removed the head and manifold as one unit. I have a spare head to match to this Super Six manifold.

My question: it is allowable, or even desirable, to mount the manifold to the head BEFORE installing the head, so I can easily get to the fasteners and facilitate making a good seal? Or MUST I torque down the head and head gasket first, then attach the intake and exhaust manifolds (which are currently in two pieces) to it?

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Never seen a Valiant I didn't like!

Totally permissible to mount the head and manifolds as a complete assy. The drawback is the weight of the unit. Makes it very difficult to set in place without hurting the head gasket. I would suggest using a engine hoist to hold the weight, and guide into place as you slowly lower.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Thanks for the quick reply Charlie.
I just read your thread in the other part of the forum- I'm really sorry about your grandson and the health issues with your wife... I'm thinking of you.
-Paul

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Never seen a Valiant I didn't like!

Get two long (at least as long as the original bolts) threaded rods and put them into opposite corners (one by the firewall, one by the radiator) of the block head bolt holes. This will let you guide the head down and have it in the right position instead of trying to rely on those tiny locating dowels in the block to get things right. Put in the center head bolts finger tight, then remove the threaded rods.

No matter when in the sequence you mount the manifolds, It is very much worth your while to get the good gaskets for the manifolds-to-head and intake-to-exhaust junctions.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks for the installation tips, regarding the use of Remflex #6008 head-to-manifold gasket kit and exhaust manifold to intake manifold heat riser gasket.

I ordered some 94358A270 threaded rods in the 5/16 size that have both the 18 and 24 thread pitch from McMaster-Carr. The little hex drive socket at the end was a nice addition to get them threaded into the engine head.


A few quick questions:

1) For both the triangular washers and the conical one, the cupped (concave) side faces the manifold/head and the coned (convex) end face out toward the lock nut, correct?
Also one, of the brass washers for the ends looks a bit malformed, and I seem to be missing one triangular washer. Can I get away with using a regular washer for the missing triangular one?

2) What is this hole in the far side of the head for? do I need to plug it? Obviously the larger one with the bolt holes on the other fae far end is for the thermostat assembly.

https://lensdump.com/i/8kJlPo

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Never seen a Valiant I didn't like!

From Slantsix Dan in that post You'll have to have a blockoff plate for the tube flange at the rear of the cylinder head. That is part number 3751 249 from the dealer (and gasket part number 4275 834).

Thanks. I ran a search of the part number and it may be difficult to find.
I took a measurement of the hole and it measures about 17.22mm/0.68", so it would seem to be 11/16" in size.
I'm going to try using a freeze plug for the 11/16 smooth hole and a manifold fastener bolt in the little machined hole next to it.

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Never seen a Valiant I didn't like!

Last time I had head installation I build Clifford and Dutra manifolds to empty head. By using a dental intraoral camera I had possibility to check inside of the hed ports. So I get manifolds positioned in the best location with no steps from manifold to head. Then I installed valves springs and retainers. And finally in team of two - me and my son we lifted the head over the ARP studs to block.

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1966 Dart. 170 cu.in. 200 rwhp.

That actually is connected to the exhaust ports, so If using a plug, goop with RTV Bronze and make sure to put some kind of plate over the plug
and use the bolt hole to hold it... or your first fire up will develop a "pop' and some fire out the hole...

Typically if there was a junkyard locally with mid-70's to early 80's mopars in it, you could find one of the charge tubes that bolts to this spot,
cut it off, hammer it flat, fold over a few times and bolt it in place to plug the hole...

I think one of the other issues faced with manifolds before head is the cast nub just above the water pump at the deck... typically I break out the
angle grinder and cut off wheel and remove that, if your manifolds are meaty like the dutra front, or off a bit, that shelf won't allow you torque the
head down correctly...