for auto and manual its 6 degrees BTDC
Inline 6 Auto: 12' BTDC Inline 6 Man: 6' BTDC 289 V8 Auto: 10' BTDC 289 V8 Man: 6' BTDC These are the factory specs. You can usually get away with a little more though.
orden de encendido ford mustang 289
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front
Original price for a 65 Mustang was $2395 I bought a new 66 289, 4 speed for $2450 and I still have it (43 years)! Never had the valve covers off.
As long as the 302 is from a similar year it will bolt right in. The only difference between the 289 and 302 is the 302 has a slightly longer stroke.
More than likely ignition timing..
Time = Distance/Speed = 289/66 = 4.37878... hours
The 3.8 liter V6 engine in a 1996 Ford Mustang has a timing CHAIN
289 with 2 barrel carb has 200 h.p.289 with 4 barrel carb has 225 h.p. 289 High Performance has 271 h.p.
A 1965 Shelby Mustang , 289 V8 , was rated at 306 BHP
Timing Chain.
C = 289 CID (2V)K = 289 CID (High Performance)A = 289 CID (4V)T = 200 CID