ConcoursMustang Forums

1st Generation 1964 1/2 - 1973 - Questions & general discussions that apply to a specific year => 1968 Mustang => Topic started by: Oz390 on September 04, 2010, 08:52:57 PM

Title: '68 390 Distributor Vacuum Advance Units
Post by: Oz390 on September 04, 2010, 08:52:57 PM

Looking to put an original dizzy (C8OF-D) back on my '68 C6 S code.  Rebuilt and recurved to factory specs.  Trying to determine:

1. was the original a single or dual diaphragm? (I have one of each)

2. what would the pros/cons be for the two units?

Title: Re: '68 390 Distributor Vacuum Advance Units
Post by: gtamustang on September 07, 2010, 02:56:20 PM

Being a 72 DSO, I would expect to see a dual diaphram vacuum advance. The two different vacuum advances was to address better emissions through the operating temperatures of the motor (cool to normal operating temp). I really do see it as a pro/con, rather it is what
Ford did to improve the emissions of the motor.

Regards,
Pete Morgan

Title: Re: '68 390 Distributor Vacuum Advance Units
Post by: Bob Gaines on September 08, 2010, 03:20:16 AM

In 68 and 69 it is common to see a big block with manual transmission using a duel advance and the automatic with a single advance. Bob