[charles bledsoe]

When I got the 66 GTO it didn't have the original engine in it. It has a 66 389, but it is for a big car I think it might be for a Catalina. It had a 2bbl carb and intake manifold on it. I changed out the manifold and put a Carter AFB carb on it. Is there a difference in the distributor for a 2bbl engine. Should I try to find a distributor for a GTO engine or will it not make any difference? The car has the original automatic transmission in it if that makes a difference.
Thanks.

[Kenth]

1966 #1111090 389 2-bbl distributor has exactly the same centrifugal timing advance as the 1966 #1111078 389/421 4-bbl distributor.
0-4°@960rpm, 12-16°@2000rpm and 20-24°@4600rpm. Add to that 6° initial.

They do use different vakuum advance though.
090 uses the #1116242 control, starts@6-8in/hg and provides max 20°@13-14,5in/hg.
078 uses the #1116243 Control, starts@8-10in/hg and provides max 20°@15-17in/hg.

[charles bledsoe]

Which vacuum advance should I use, the 048 for the 4bbl? Thanks for the response!!

[charles bledsoe]

I never did get a response back from the question above on which vacuum advance canister to use. Does anyone know?
Thanks.

[Kenth]

I wouldn´t change the 2-bbl vacuum advance unless it´s broke or makes part throttle ping.
If ping occurs at part throttle acceleration you may reduce the amount of advance by shortening the slot, one quarter of the total distance, for approximately 15° advance.

If you need a new vacuum advance, Standard Motor Products got the VC24A (Dana B1) to replace both the 1116242 and the 1116243 controls.
Starts@8-11in/hg and gives max 16°@16-18in/hg.

Hope this helps some....

[SD421]

Originally Posted by Kenth

1966 #1111090 389 2-bbl distributor has exactly the same centrifugal timing advance as the 1966 #1111078 389/421 4-bbl distributor.
0-4°@960rpm, 12-16°@2000rpm and 20-24°@4600rpm. Add to that 6° initial.

They do use different vakuum advance though.
090 uses the #1116242 control, starts@6-8in/hg and provides max 20°@13-14,5in/hg.
078 uses the #1116243 Control, starts@8-10in/hg and provides max 20°@15-17in/hg.

My 1966 GTO Shop Manual shows different info.

Dist# 1111078 is for a 389 4-barrel
0-2°@480rpm, 6-8°@1000rpm and 10-12°@2300rpm.

Dist# 1111054 is for the 389/421 Tri-Power
.5-2.5°@450rpm, 8-10°@1150rpm and 10-12°@2300rpm.

Vacuum Advance Model #is:
1116243 for the 4 barrel
starts at 8-10
full advance 15-17
max is 10 degrees

1116172 for the Trips (tripower)
starts at 8-10
full advance 14.75-16.75
max is 10 degrees
Don

BTW Wild about Cars has a great website where you can download the manuals for free
(you do have to register). Great source of factory lierature
http://wildaboutcarsonline.com/cgi-b...=9940395242400

[Kenth]

Originally Posted by SD421

My 1966 GTO Shop Manual shows different info.

Dist# 1111078 is for a 389 4-barrel
0-2°@480rpm, 6-8°@1000rpm and 10-12°@2300rpm.

Dist# 1111054 is for the 389/421 Tri-Power
.5-2.5°@450rpm, 8-10°@1150rpm and 10-12°@2300rpm.

Vacuum Advance Model #is:
1116243 for the 4 barrel
starts at 8-10
full advance 15-17
max is 10 degrees

1116172 for the Trips (tripower)
starts at 8-10
full advance 14.75-16.75
max is 10 degrees
Don

BTW Wild about Cars has a great website where you can download the manuals for free
(you do have to register). Great source of factory lierature
http://wildaboutcarsonline.com/cgi-b...=9940395242400

My info is from the 1966 Tempest Chassis Shop Manual.
The only difference is that your info is on distibutor degrees and my info is on crank degees, as i´ve found it is easier to check timing on engine directly than to buy a SUN distributor machine.
The crank turns two revolutions while the distributor turns one revolution.
This means you´ll have to take distibutor degrees times two.

[charles bledsoe]

Originally Posted by Kenth

I wouldn´t change the 2-bbl vacuum advance unless it´s broke or makes part throttle ping.
If ping occurs at part throttle acceleration you may reduce the amount of advance by shortening the slot, one quarter of the total distance, for approximately 15° advance.

If you need a new vacuum advance, Standard Motor Products got the VC24A (Dana B1) to replace both the 1116242 and the 1116243 controls.
Starts@8-11in/hg and gives max 16°@16-18in/hg.

Hope this helps some....

Thanks Kenth!! Found the part at Rock Auto. It was $10.80. Will pick it up and try it out.
Chuck