Head question

[saltwaterfalcon1960]

I read the sticky on heads and still could not find answer to my question,so here it is.
Will a 1966 200 head work on a 1966 170? Both engines are stock.

 

[Asa]

it will bolt straight onto it, yes
however, you'll need to do some moderate work to the new head to get it to work correctly

main thing this would be is getting it milled slightly to offset the thicker gaskets used today (unless you want something like 7.5:1 compression ratio)
it would also be a good idea to check the combustion chamber size and make sure there's not a huge difference there

the heads bolt straight on, but the head FAQ is for stuff like the CR

 

[saltwaterfalcon1960]

HI,
Thanks for the reply.
Will it run ok with 7.5 to 1 compression?Not looking for performance at this time.Just want to get car running.

 

[wallaka]

It'll run, but gas mileage and power will take a fairly large hit.

 

[saltwaterfalcon1960]

Thanks guys.
You saved me from making a big mistake.I have a 200 3-1bbl head.I wanted to put that head on the 170.However now I know to forget that.I will just put the 170 in as is.Thanks again.

 

[61Futura]

Whoa there! If you've got 3 good carburetors to go with that head, I would not give up on that 200 head so quick. It probably has the same chamber cc's as a 170 head from the same year. Getting the carbs set up would be a trip. Either head will need to be milled for the thicker head gasket unless you find & use a steel gasket. Use a 170 gasket if its steel. It should have slightly smaller bore than the 200 gasket.

 

[CZLN6]

Howdy Saltwater:

The only way to know for sure, on CR is to measure the combustion chambers volume on both heads in CCs and do the math.

The casting numbers of the two heads will tell somethings too. Well, actually, the suffix, after the C6DE 6090, there will be one or two letters, X or XX. These letters identify C/E heads from others).

For all practical purposes, the '66 170 and 200 OEM heads were identical, given the same casting numbers and suffixes. And, it is not unusual to find C5xx castings on '66 model year engines. The valve size is the biggest difference between '63 castings and later. Some C3 castings found their way onto '64 model years. If the valves measure 1.64" intake and 1.38" exhaust, the heads, for all practical purposes, are the same.

The composite aftermarket head gasket, all else being equal, will account for a half a point loss of CR. If the stock '66 170 was rated at 9.2:1, and nothing else but the head gasket was changed, it would likely change the CR to 8.7:1.

As usual, the devil is in the details.

Adios, David

 

[saltwaterfalcon1960]

Just took the valve cover off the 1966 170 I am replacing blown 200 with and it has adjustable rocker arms from earlier solid lifter engine.What is the purpose of that?
C6DE on block confirms that this engine is a 1966.Also has metal tag that says 1966 170.Funny thing ,the heads of both the 170 and 200 have the exact casting numbers followed by a big X6 .These numbers are cast into intake log.1966 170 came out of bronko.the blown 1966 200 was in mustang.Weird ???

 

[JackFish]

That adjustable rocker is somewhat rare, and quite handy if you mill the head or block. It can be used with hydraulic lifters, and necessary if there's solid lifters in there.