I recently purchased a 1975 model year 351W
that was originally installed in a E-series
van and later transplanted into a F-series
pickup. Currently, it has a flexplate for
automatic transmission in it, and I want to
convert it to a manual transmission flywheel.
The question I have is this:

What is the balance on the 1975 model 351W ?
The flexplate on this engine seems to be zero
external balance, like the I6-300; I cant find
any additional weights welded to that flexplate
anywhere. The flywheel I have for a 302/351W
has the standard 28 oz balance on it. Did
someone change this engine? or did they just
put the wrong flexplate on and get lucky that
the engine didnt tear itself apart?

 

I believe 28oz is correct. Also check the harmonic balancer. I put a mid 80's 302 in an early Bronco and had fun. Had to change the flywheel and balancer.

 

>I recently purchased a 1975 model year 351W
>that was originally installed in a E-series
>van and later transplanted into a F-series
>pickup. Currently, it has a flexplate for
>automatic transmission in it, and I want to
>convert it to a manual transmission flywheel.
>The question I have is this:
>
>What is the balance on the 1975 model 351W ?
>The flexplate on this engine seems to be zero
>external balance, like the I6-300; I cant find
>any additional weights welded to that flexplate
>anywhere. The flywheel I have for a 302/351W
>has the standard 28 oz balance on it. Did
>someone change this engine? or did they just
>put the wrong flexplate on and get lucky that
>the engine didnt tear itself apart?


All 351's are 28oz. Only the 302's changed. Typical Ford! LOL!!

Seems strange about your flexplate. All mine,302 or 351, have a weight welded on.