I was trying to decode my friend's 65 fastback on www.mustangdecoder.com and this is what it shows for this warranty # 5R09F178789

5 1965 (1964 1/2)
R San Jose
09 CODE NOT FOUND
F 260 2V V8
178789 Unit number

My question is, why on body series the 09 don't show as a 2+2 fastback? it has something to do that a 260 engine was on 1964 1/2 models and the first fastback models was introduced on 1965?

 

http://www.mustangspecs.com/years/64-65.shtml
According to this reference website, the '09' verifies that this is a Fastback Mustang.
[blockquote]
Vehicle Identification Numbers
[/size]Engine Codes[/font]



170cid 1V 6cyl 101hp (1964½)
U

200cid 1V 6cyl 120hp (1965)
T

260cid 2V V-8 164hp (1964½)
F

289cid 2V V-8 200hp (1965)
C

289cid 4V V-8 210hp (1964½)
D

289cid 4V V-8 225hp (1965)
A

289cid 4V V-8 271hp high performance (1965)
K[font=verdana][size=1]
5 - Last digit of model year (1965)
F - Assembly plant (F-Dearborn, R-San Jose T-Metuchen)
07 - Body code (07-Coupe, 08-Convertible, 09-Fastback)
F - Engine Code
100001 - Consecutive unit number
Example: 5F07F100001 [/blockquote]