1966 Mustang – Distributor Information

1966 Ford Mustang Distributor Information & Specs

Ford used 3 kinds of distributors on 1966; the Loadomatic, a Dual Advance and a Centrifugal.

Distributor General Information

170 and 200 cubic inch inline six cylinders all had a breaker arm spring tension of 17-21 ounces. contact spacing was 0.025 and the dwell at idle speed was 37-42 degrees. End shaft play with the distributor removed is 0.022-0.033 inches and the distance from the bottom of the mounting flange to the bottom of the gear is 2.510 – 2.515 inches. Timing for 200 ci engines with a manual transmission is 6 degrees before top dead center (BTDC), for automatics it is 12 degrees BTDC.

289 and 390 cubic inch V8 engines all had a breaker arm spring tension of 17-21 ounces. contact spacing was 0.017 and the dwell at idle speed was 26-31 degrees. 289 end shaft play with the distributor removed is 0.024-0.035 inches while the 390’s end shaft play is 0.022-0.032 inches. The distance from the bottom of the mounting flange to the bottom of the gear for the 289 is 4.0131-4.038 inches and for the 390 is 3.071-3.077 inches. Timing for 289 ci engines with a manual transmission or automatic is 6 degrees before top dead center (BTDC). Timing for a 390 is 10 degrees BTDC.

289 High Performance 8 cylinders had a breaker arm spring tension of 22-30 ounces. contact spacing was 0.020 and the dwell at idle speed was 30-33 degrees. 289 HiPo end shaft play with the distributor removed is 0.024-0.035 inches. The distance from the bottom of the mounting flange to the bottom of the gear for the HiPo is 4.0131-4.038 inches. Timing for 289 ci engines with a manual transmission is 12 degrees before top dead center (BTDC). The mustang did not receive an automatic behind the HiPo engine.

For high altitude operations, the timing for all engines can safely be advanced up to a maximum of 5 degrees. Another method for setting the timing for optimal performance is to turn the distributor to obtain the highest maximum RPM, then back it back 50 degrees. We used this method back in the 1960’s when we raced cars. If you live in the mountains and are used to getting crappy low octane gas, you can retard the spark settings to eliminate knocking and pinging. Reduce timing to a maximum of 2 degrees.

Application Table

Advanced characteristics

Advanced characteristics apply to that distributor only. Refer to the tag on the distributor for the correct code.

C5DF12127-C
VACUUM ADVANCE – perform test at 250 RPM and 0 inches of mercury
Distributor RPM
Advance Degrees
Vacuum inches of mercury
800
2.5 – 3.5
0.8
1200
6.5 – 7.5
1.8
1800
8.75 – 10
3.0
2000
10.25 – 11.25
3.9
Maximum advance limit is 14.5 degrees

 

C5DF12127-E
VACUUM ADVANCE – perform test at 250 RPM and 0 inches of mercury
Distributor RPM
Advance Degrees
Vacuum inches of mercury
600
1 – 2
0.44
800
5 – 6
1.80
1200
8.25 – 9.25
1.90
2000
10.25 – 11.50
3.80
Maximum advance limit is 15.5 degrees

 

C5DF12127-K
VACUUM ADVANCE – perform test at 250 RPM and 0 inches of mercury
Distributor RPM
Advance Degrees
Vacuum inches of mercury
800
.75 – 1.75
.79
1200
3.75 – 4.75
1.90
1600
5.75 – 7
3.00
2000
7 – 8.25
3.80
Maximum advance limit is 12.75 degrees

 

C5AF-12127-M
CENTRIFUGAL ADVANCE – perform test at 250 RPM and 0 inches of mercury
Distributor RPM
Advance Degrees
Vacuum inches of mercury
650
1.5 – 2.5
0
800
4.75 – 5.75
0
1200
8.5 – 9.5
0
1600
10.25 – 11.75
0
2000
12 – 13.75
0
Maximum advance limit is 14.0 degrees
VACUUM ADVANCE – perform test at 0 degrees and 1000 RPM with 0 inches of mercury
Distributor RPM
Advance Degrees
Vacuum inches of mercury
1000
1.5 – 4.5
8
1000
3.5 – 6.5
10
1000
6.75 – 9.75
14
Maximum advance limit is 12.5 degrees

 

C5AF-12127-N
CENTRIFUGAL ADVANCE – perform test at 250 RPM and 0 inches of mercury
Distributor RPM
Advance Degrees
Vacuum inches of mercury
450
1.5 – 2.5
0
600
5.25 – 6.25
0
800
7.25 – 8.25
0
1400
8.75 – 10
0
2000
110.5 – 12
0
Maximum advance limit is 14.0 degrees
VACUUM ADVANCE – perform test at 0 degrees and 1000 RPM with 0 inches of mercury
Distributor RPM
Advance Degrees
Vacuum inches of mercury
1000
1.5 – 4.75
8
1000
5 – 8
10
1000
8.25 – 11
14
Maximum advance limit is 12.5 degrees

 

C5OF-12127-E
CENTRIFUGAL ADVANCE – perform test at 250 RPM and 0 inches of mercury
Distributor RPM
Advance Degrees
Vacuum inches of mercury
650
2.25 – 3.75
0
750
4 – 5.5
0
1000
6.5 – 7.5
0
1600
7.5 – 8.75
0
2000
8.25 – 9.75
0
Maximum advance limit is 14.0 degrees

Distributor Technical Drawings

6 Cylinder Distributor

66 Mustang Distributor - 6 Cylinder

8 Cylinder Distributor

66 Mustang Distributor - 8 Cylinder

Stamped Weight Distributor

66 Mustang Distributor - Stamped Weight