170 head on 200

[mysavioreigns]

Guys, I know changing the head from one ci to another will physically bolt up but will change the CR. How will a 1970 170ci head put on my 1966 200ci measure up? Will I need to go any larger with any kind of gaskets? I read the article on the sticky about the 144-250 head swap, and it gave examples (like putting a 144 on a 250, and vice versa) but it's not that big of a gap, so I don't know.

Also, according to the article, doing this will have too much compression. It will also lack the ability to breath. Will putting the Holley/Weber 5200 and larger exhaust cause this to have more problems with breathing or help it?

 

[CZLN6]

Howdy MSR:

I don't believe they will have different size chambers. The only way to know for sure is to measure. Some 170s in this time frame still had small 52 cc chambers, same as a '66 200.

It is very likely that the only differences between the '66 200 head and the '70 170 head will be that the '70 head will have a 1.75" carb hole as opposed to a 1.5" on the '66. The '70 will also likely have induction hardened valve seats.

Both will have 1.649" intakes and 1.38 exhaust. Look at the log style closely.

A two barrel and better exhaust will help either of these heads.

Hope that helps you.

Adios, David

 

[mysavioreigns]

Thanks David,

I do know that this one has hardened seats (new) and it looks like the carb hole is a 1.75". I can't find my ruler Thanks again for the specs