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86 head on a 64
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Author:  scottyv [ Tue Sep 22, 2015 8:02 am ]
Post subject:  86 head on a 64
howdy all, been having some issues with my slant the original head has some "sticky" valves and needs guides and seats, a guy I know has an 86 head in good shape, rather then spend $400 on a head job LOL!!! I'm thinking of just swapping in the new head, can I just put it in using my original rocker arm and bolts are they the same length bolts and stuff ?
Author:  scottyv [ Tue Sep 22, 2015 8:03 am ]
Post subject: 
also my 64 is a 170 not a 225
Author:  Reed [ Tue Sep 22, 2015 9:08 am ]
Post subject: 
The 86 head will physically bolt to the 64 170 no problem. You will have to be careful about the rocker arm hardware, though.

In the late 70s Chrysler switched from the single diameter rearmost rocker arm shaft bolt to a stepped bolt. Accordingly, the rearmost hole in the rocker arm shaft change from the same size hole top and bottom to a large hole on top and a smaller hole on the bottom.

If you put the 86 head on a 64 170 you will have to use the rearmost rocker arm shaft bolt from the 86 head. However, in 1981 Chrysler also introduced hydraulic lifters to the slant six. Switching to hydraulic lifters necessitated a change in the design of the rocker arms and the rocker arm shaft. The hydraulic cam rocker arms are not adjustable and the hydraulic cam rocker arm shaft has the rocker arm oiling holes drilled at a different orientation than the mechanical camshaft rocker arm shaft. The rocker arms and rocker arm shaft from a hydraulic lifter motor cannot be used on a mechanical lifter engine. You will need adjustable rocker arms and the rocker arms will not be oiled properly.

To make the 86 head work correctly on your 64 engine, you will need to use the rocker arms and spacers from the 170, the rearmost rocker arm shaft bolt from the 86, but you will need to find a rocker arm shaft from a late 70s mechanical camshaft motor that had the stepped rearmost rocker arm shaft bolt.

A few years back I switched an engine from a mechanical lifter setup to a hydraulic lifter setup and I documented the various differences between the two systems. See HERE.
Author:  scottyv [ Tue Sep 22, 2015 11:44 am ]
Post subject: 
I planned on using my rockers, pushrods and rocker shaft anyway because of the mechanical/ hydrolic difference, so all I really need is the rear bolt, mine was smoking bad so I put valve seals in and while I had it apart noticed 2 bent pushrods but all else seamed OK so I replaced the 2 put everything together adjusted them started car and bent the same 2 I also noticed that the valve and spring were still pushed down even with no pushrod so I removed the head tapped valves with hammer and they returned to closed, not sure if there bent or just rusty from sitting for 29 years, luckily no damage to the pistons the local shop want $500 to redo the head, which is way too much but I don't have the time or patience for the job :)
Author:  scottyv [ Tue Sep 22, 2015 11:51 am ]
Post subject: 
OK I'm a retard I just read the thing again, so I'll use my stuff, the 86 bolt and a newer mechanical shaft :)
Author:  NEVjr [ Tue Sep 22, 2015 3:05 pm ]
Post subject: 
what would happen if the oiling holes on either shaft were elongated with a cut off wheel on a die grinder to give oil a passage to match the other shaft? similar to the groove on the cam bearing but only part way around. would that simplify the swap?
Author:  Reed [ Tue Sep 22, 2015 3:43 pm ]
Post subject: 
Possibly, but after a certain point I would be worried about oil pressure loss. Granted, the rocker arm shaft doesn't see high pressure, but 12 big holes/gashes in the shaft might lead to structural weakness or dropped oil pressure. There is a reason Chrysler saw fit to just drill a hole.

I suppose redrilling the 12 holes at a different orientation would be fine, so long as the rocker arm shaft was cleaned out of any shavings.
Author:  scottyv [ Thu Sep 24, 2015 3:58 pm ]
Post subject: 
anybody got an early head around in good shape ???
Author:  Reed [ Thu Sep 24, 2015 5:00 pm ]
Post subject: 
If you don't want to mess with the stepped bolt issue then you can use any head pre 1977.
Author:  scottyv [ Thu Sep 24, 2015 7:44 pm ]
Post subject: 
anybody have a per 1977 head in good shape ?
Author:  Reed [ Thu Sep 24, 2015 9:23 pm ]
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Tell you what, use the 86 head and the rearmost rocker arm shaft for the 86 head, and use the rest of the rocker assembly from your current head.
Author:  scottyv [ Fri Sep 25, 2015 4:38 am ]
Post subject: 
stupid auto correct, that's "pre" 1977 head not "per"
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