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Ford In-line 6 Cylinder Bell Housing, Starter, & Clutch Match-up

Need help determining which Ford In-line 6 you have? This article takes away the guess-work when it comes to getting the right components for the flywheel, clutch and starter by showing you the back of the block and what to look for.


Ford In-Line 6

This article works with our “6 Cylinder Bell Housings” article.

The Ford In-line 6 cylinder used in passenger cars and Econolines came in 3 sizes in the 60’s and 70’s: 144, 170 & 200 c.i. displacements.  Also used in various vehicles were 240, 250 & 300 c.i. displacements.  The focus of this article does not include those engines.

Easily recognizable are the 144 & 170 engines which have only 3 freeze plugs on the passenger side of the block, while the 200 engines have 5 freeze plugs on the passenger side of the block.  It is possible early 200 engines have 3 freeze plugs, but don’t quote me on that.

The confusion comes in when trying to determine which flywheel, clutch and starter to use. The below pictures and dimensions will clarify this and show an example of the 8.5” set-up being installed.

Shown above is what we call a “dual pattern block”. It has both 8.5” and 9” bell patterns and can be used for either set-up.

The “set-up” has 5 things that must match with each other:

  • Engine block,
  • engine block plate,
  • flywheel,
  • clutch (disk and pressure plate),
  • starter.

You either use the 8.5” set-up, or the 9” set-up.  Do not try and mix/match. It will not work.

There are 4 holes that hold the bell housing to the block. The bottom two holes, in line horizontally with the crank, are the same whether you have the 8.5” or 9”. The top two holes are variable depending on whether you have an 8.5” or 9” engine block.

Not all engine blocks are “dual pattern”. The 144 & 170 engines only had the 8.5” set-up. The early 200’s, 1964-66, used the 8.5” set-up. The mid 200’s, 1965-68, had dual pattern blocks. And the late 200 block castings, 1967-1979 only had the 9” set-up. On a side note, the last 200’s, 1980-83 shared the V-8 Small Block Ford block casting. Since I don’t have all the block casting numbers and we’ve had customers with various “stock” configurations, it’s anyone’s guess as to the methodology Ford used to determine which car got what block/trans in the 60’s.

So the best way we know is to measure horizontally between the top two bolts. Notice on our picture with the fingers we are pointing at the 8.5” and 9” patterns. Our block had an 8.5” bell housing installed, based on the wear pattern in the paint. See the last page for some block part numbers.

The measurements from center of bolt to center of bolt are:

  • 8.5” - 4.75” center to center
  • 9” - 5.5” center to center

Above we show a dual pattern block with an 8.5” set-up: 3-bolt starter block plate, 132 tooth flywheel, and stock 8.5” clutch.


Shown above is an 8.5” flywheel being installed.

The 8.5” flywheel is Dog Dished while a 9” flywheel will be flat with a slight machined lip in some cases. Be sure to use thread sealant on the flywheel bolts or prepare for a wet slipping clutch.

Shown above is an 8.5” Tremec T-5 change-over clutch set being installed.


Here is a picture of an 8.5” bell with Modern Driveline adapter plate and Tremec T-5 transmission. This is installed in a 1965 Mustang with mechanical linkage.


Here are some Block casting numbers:

C5DE 6015-H      Early 200 I-6, 5 freeze plugs, 8.5” pattern only.


Modern Driveline offers complete solutions for the In-line 6 cylinder engines. The installation of an overdrive transmission will increase the drivability of your car, enhancing your driving experience and increasing mileage.