My 1965 F100 8' Styleside came with 352/T85N O/D and 7.75-15 bias ply tires.

I would assume 'smoked chicken's' 66 F100 came with these same sized tires.

The thing is, does this truck have a 9 3/8" ring gear? Different R&P (and damn near everything else!) than a 9.

Carrier looks different than 9 // 9 3/8" upper horizontal boss curves downwards on left (drivers) side. 9" goes straight across.

 

hello jeffafa......the difference between 2.78 and 2.75 is just approximately 0.37 mph per 1000 rpms but then again i don't begin to wanna know about tire growth formula's so don't need a perfect scientific exact number just close ball park....and to help you out tape measure says 30" true diameter...

 

I found this so far.*********** 1949to1964 1965to1970 1970 to 1980 1960 - On 1980 - On NUMERIC ALPHA NUMERIC* EURO-METRIC P-METRIC EURO-METRIC or P-METRIC "90-" to "80"-series 78- to 50-series "82"-series 80-, 75-series 70-series 65-series 60-series 50-series 5.20-10 145R10 165/70R10 5.20-12 145R12 P145/80R12 165/70R12 5.60-12 6.00-12 155R12 P155/80R12 165/65R13 145R13 155R13 P155/80R13 175/70R13 195/60R13 215/50R13 5.60-13 6.00-13 A 165R13 P165/80R13 185/70R13 205/60R13 6.50-13 B 175R13 P175/80R13 C P185/80R13 7.00-13 D 185R13 195R13 5.60-14 6.00-14 145R14 175/65R14 6.00-14 6.45-14 155R14 175/70R14 185/65R14 B 165R14 P175/75R14 185/70R14 195/65R14 205/60R14 6.50-14 6.95-14 C 175R14 P185/75R14 195/70R14 215/60R14 D 7.00-14 7.35-14 E 185R14 P195/75R14 205/70R14 225/60R14 245/50R14 7.50-14 7.75-14 F 195R14 P205/75R14 215/70R14 235/60R14 8.00-14 8.25-14 G 205R14 P215/75R14 225/70R14 245/60R14 265/50R14 8.50-14 8.55-14 H 215R14 P225/75R14 9.00-14 J 225R14 9.50-14 L 5.60-15 A 155R15 P155/80R15 185/65R15 195/60R15 6.00-15 B 165R15 P165/80R15 185/70R15 195/65R15 205/60R15 225/50R15 6.50-15 6.85-15 C 175R15 195/70R15 205/65R15 215/60R15 D 7.35-15 E 185R15 P195/75R15 205/70R15 215/65R15 225/60R15 6.70-15 7.75-15 F 195R15 P205/75R15 215/70R15 235/60R15 8.15-15 7.10-15 G 205R15 P215/75R15 225/70R15 235/65R15 245/60R15 265/50R15 8.25-15 8.45-15 7.60-15 H 215R15 P225/75R15 235/70R15 255/60R15 275/50R15 8.55-15 8.00-15 8.85-15 J 225R15 P225/75R15 235/70R15 265/60R15 8.20-15 9.00-15 K 9.15-15 L 235R15 P235/75R15 255/70R15 275/60R15 295/50R15 N * When replacing Alpha Numeric tires with Euro-metric or P-metric tires, look for the Euro-metric or P-metric size listed in the equivalent aspect ratio. For example, when replacing a FR78-14, you would look up the appropriate 75-series size, the 205/75R14. If replacing a FR70-14, you would look up the appropriate 70-series size, the 215/70R14. If replacing a FR60-14, you would look up the appropriate 60-series size, the 235/60R14.•Listing in chart does not imply complete interchangeability. •When changing tire sizes, dimensional clearances must be checked. Close Window
EDIT. For some reason my computor is not pasting it in the original chart form.

 

smoked chicken lol Bill........ the name smokenchoken comes from an old man that when ever i would drive my 67 it would smoke n choke him out with the motor smoke and tire smoke when he was sittin on his porch ...... i dearly miss that old man he was one of my true hero's......so the 67 became known as smokenchoken

 

Since 2.75's and NP435 is impossible, one has to improvise. 2.75's not listed in 1964/72 catalog. So...see 2.75 .. 3 M/T below.

DRIVE gear: D7TZ-17285-A = 9T.

DRIVEN gears: C3DZ-17271-B = 17T / C0DD-17271-B = 18T / C0DD-17271-C = 19T

I haven't gotten around to figuring out what the original configuration was: Dana 60.2 with NP435 & 4.10 ratio, 15" wheels.

 

hello... Bill... remember the part about the rear end gears coming from some unknown land yacht..... the guy is a mechanic and racer he also buys cars gets the parts worth keeping and scraps the rest he has a big shop full of good parts that i look through occasionally... i never said this gear ratio came in a ford pickup at any time with or without a 435 np but i am saying it has 2.7x gears in the 9" that came out from under my old 67 in place of the dana 60.2...... the transmission is a 435 np out of a 76 f250 parts truck....... the truck came with a 352 i took that motor out installed a 391 FT drove it for a year and a half motor spun a bearing now it has a 1971 360 with the 66's heads and a hundred other little changes that are not in any book any where i can list and go on and on about the things that are there that shouldn't be and all your books will say that it is not but when it bolts up and gets the job done it works....adaptation and improvisation is the KEY my dearest Numberdummy

 

so was 2.78 gears ever offered in any FORD, LINCOLN, or MERCURY i have asked this before and no one has ever corrected me or told me they were......also don't factor out the other differentials that can bolt onto the 9" (like the 9 3/8" IIRC)

 

No such thing as a 9 or 9 3/8 w/a 2.78 ratio.

Lowest numerical ratios: 9 = 2.47 - 2.50 - 2.75 / 9 3/8 = 2.80.

2.75's first offered in F100's in 1973, 2.47 & 2.50 offered in land yachts (1977/78 LTD/Grand Marquis & 1977/79 Town Car) after the first Arab Oil Embargo (1973/74) ended. Another occurred in 1979.

During the first embargo, people for the first time since during WWII (when gas was rationed), were concerned about MPG

LTD/Grand Marquis downsized in 1979, Lincoln in 1980, were no longer available with 9's. Passenger Cars: Last 9 installed in 1980 Granada/Monarch/Versailles, also came with rear discs.

 

ok Bill thank you it must have been a misread on his part and poor information on mine thank you for your knowledge all my post from here on out will be 2.75 gears instead of 2.78......so jeffafa have you figured out the calculations needed yet or a rough count at least?

 

JEFFAFA is a Ford partsguy working at a dealer in Arid-Zona. Answers the 'wholesale' parts phone lines.

If someone phones in a body order, it'll take him some time (if VIN unavailable) to look up all the crap, type it into 'puter. More time if he has to pull all the parts.

And every so often, the Big Dummy calls, wasting JEFFAFA's time with stories from the past.

Personally, I don't see how he finds the time to spend on FTE. When I was working, just finding time to go to lunch could be a PITA

 

Phones kept me busy all afternoon. I did get as far as seeing tires on there now are a LOT taller than Ford lists. Most 4.10/4.11 trucks had 6 tooth DRIVE gears. Nothing listed smaller numerically than 3.00. To make a long story short let's call that an 8 tooth gear. 69 and older was different than 1970/72. I didn't see untill now it's got a 1976 4 speed.

 

Back in the Bump's day 3sp and 4sp's took the same gear. But looking at Bill's chart above it shows them taking different DRIVE gears. I would go with the gears listed under "3.00" and change from there to dial in.