Wasn't the stock ratio for the 66 V8 a 2.79?
Am I correct in assuming this is a pretty slow gear off the line, like almost to the point where you feel like you have to ride the clutch from a stop or it will feel almost like it wants to stall?
I've owned several '66 V8 Mustangs, and looked at a lot more.
Every C code I ever saw came with 2.80 gears.
Every A code I ever saw came with 3.00.
K codes varied from 3.50 on up.
I'll also throw this in: every T code Mustang I've seen had a 2.83 rear axle if it was an automatic car, and a 3.20 if it was a stick.
FYI, the 2.79 ratio didn't appear until '67 or '68 (I forget which).
You would probably enjoy your car a lot more with 3.25 or 3.50 gears.
"When a woman is a really good driver, she is just about perfect."
- Raymond Chandler
'66 GT Fastback show car, nightmist blue, warmed up original 289 & T-5Z, 3.80 trac-loc, AC, PS, pony interior, Retrosound, rally pac
'66 Coupe driver, Bullitt green, 302HO w/ 351W heads, roller rockers, Holley 600, T-5Z, 3.55 trac-loc, collapsible column, tank armor, disk brakes, shoulder belts
'11 BMW 335i X-drive, 6 speed manual, all the bells and whistles