250 Head mill specs

[FastRonald]

8) What is the average or recommended amount milled off a 250 head to bolt on to a 1981 200 block?

 

[Anonymous]

Ronald,

Welcome to the forum!!

You should mill off (at the very least) around .020 so you can make up the differance between the original "steel shim" head gasket and the "composite" gasket that is available nowadays.

You should cc the combustion chambers and run it through a compression calculator to figure out what your final compression ratio will end up being.

Heres a calculator link,

http://falconperformance.sundog.net/compcalculator.asp

Usually on a street car, you want to keep the compression ratio between 9.0-9.8:1 depending on what you are planning on doing with it.

Hope this helps!

Later,

Doug

 

[CZLN6]

Howdy Back FastRonald:

A couple of things; 1st read the sticky post at the top of this forum for details on the difference of compressed thickness of head gaskets, 2nd, all 200/250 casting are the same. For example, a head with a D3DE-AA casting # from 1973 and after would be used on either a 200 or a 250 block. The difference in compression was in the deck height, And 3rd a head from an '81 block would likely have an E0BE casting mark and a chamber volume of aproximately 62 cc.

So to be accurate and specific, what is the casting # of the "250" head you plan to use? And Doug's advice to CC the chamber of the "250" head is right on. You never really know what has been done to a head in the last 40 years and the only way to know for sure is to measure it yourself.

Adios, David