I found the data plate in the TRUNK under new carpet, PO must have stashed it there for some weird reason...

Year: 9 1969
Plant: R San Jose, CA
Body Series: 01 2 Door Hardtop
Engine: M 351 4v V8
Unit: 141182 141182

Miscellaneous Vehicle Data Body: 650 code not found
Color: F Gulfstream Aqua Metallic
Trim: 8A Black Vinyl with Black Knitted Vinyl, Bench Seat, Standard Interior
Date: 03B February 03, 1969
D.S.O: 72 San Jose
Axle: 6 3.00:1, Conventional
Trans: X FMX Automatic


Two obvious things I noticed:

"351 4v V8" - was that a Windsor?
"FMX Automatic" - well, it's a 4spd. now, so what's the easiest way to ID the new tranny?




so exciting! it's like an adopted kid finding their real parents!

 

yes, i believe so

 

Where have you been my whole life

 

All 69 Mustang 351 CID engines were Windsors. Off hand, I would suspect that your 4 speed is a top loader, they are more available than T-10s. Look for an ID tag or get a casting number if you are not familiar with the visual differences.
Jim