Rearend gears with a 302 and C4?

[Kraig]

My truck originally had a six banger with a 3 speed and 3.73 gears. It now has a 302 and a C4. It screams along pretty good at 60 !! What gearing normally came in a truck with this drive train? It's not much of a freeway cruiser at this point.

[DuckRyder]

My 360/C6 truck is a 3.50. I think 3.00/3.25/3.50 are all reasonably common in the V-8 trucks.

Personally, I'm thinking a 4.56 might be appropriate for the rear end overhaul on mine, but that's another story. :twisted:

IIRC, someone said last week that the 6 banger trucks were commonly 3.70-3.90.

[NM5K]

Being that engine/tranny more suited to highway/street, vs pulling, offroad, etc, I think I would switch on up to the 3.00 or so...
Hummm, is that a F-250??? The 3.73 was used in the dana 60... Normally, a
1/2 ton ford rear of that range would be a 3.70. Anyway, if you do have a dana 60, and a 3.73, your options with that same carrier are the 3.33 and the 3.54. Also, the 4.10, but you don't want to go there...The 3.33 is an aftermarket gear...Ford didn't sell those, but you can get it...
If it is a ford with a 3.70 by chance, the options higher would be 3.50, 3.25 *I think*, and the 3.00. Maybe others I don't know of...Myself, I'd probably go pretty high geared, if you want a good highway cruiser...MK

[Kraig]

You're right, they're 3.70s.

[SVT522]

Put an AOD in it!

[willowbilly3]

How tall are your tires? My 300-6 with 3.73s and 31 inch tires runs right along at 70-75 with out complaining. 3.25s seem to be the most common and I would go numerically lower with a 302 or it will be a dog IMO. 3.50s are a good all around gear for decent power and good cruising.

[fisheye]

I have a '70 F-100 SWB Sport Custom that came from the factory with a 302, C-4 and Ford 9" with 3.50 gears. I installed new tires, Goodyear GTII Eagles P255/60 R15's, and it turned 2900 rpm at 70 mph. I have swapped out to an AOD and the same rear end now turns 2100 at 70 mph. A big difference and a lot nicer to drive. Here is a tip for those who are thinking of an AOD, just remember that it was the first overdrive automatic and it is not as strong as the newer ones. If you are going to build the engine at all I recommend that you buy a performance model and install a hardened input shaft that drives the overdrive. I have about a 1000 miles on mine and finally figured out the right adjustments to the TV pressure and it works great now and spools up just as fast as the C-4. What a difference to drive with better gas mileage and lower noise and it is just more confortable. fisheye

[wekelm]

I've got a 71 with 302 and C-4. it came with 3.25 gears. i'm think of changing to 3.50 or 3.73s myself. How ever with 31 inch tires it does cruise pretty good.

[fordxxx]

Fisheye, what flexplate did you use with your '70 302/AOD? I was thinking of doing the same swap and figured a 351/AOD flex plate would be needed...is that true?

Thanks

[fisheye]

I used a BM flexplate with the heaver balance weight required for the new crate motor. Be sure you use the right flexplate for the engine balance requirements. It is a 302 flexplate and I bought it new on eBay from a guy that didn't use it.

[fisheye]

I used a BM flexplate with the heaver balance weight required for the new crate motor. Be sure you use the right flexplate for the engine balance requirements. It is a 302 flexplate and I bought it new on eBay from a guy that didn't use it.

PS Mustangs came with a AOD and a 302 from the factory.

[fordxxx]

I thought Fisheye was using the original 70 302. I have the original 302 in my 72 so I need 28oz balance flex plate. That is why I was thinking of the 351 flex plate because they are all 28oz balance.

Has anyone done an AOD to early 302?

[spartman]

Don't forget about the full size fords and mercs for AOD's

As long as you aren't using it to pull stumps they will work just fine with a few needed updates.

[cdeal28078]

Fisheye, what kind of mileage are you getting with you 302/AOD combo? I have a 351w/AOD with 3.70 gears and am very un-happy with my mileage. I get around 13 mpg on the interstate BUT I realize I now drive alot faster.
I have a Stealth intake, Compcams Extreme 4x4 cam and a Holley 600 on mine plus all MSD ignition.
I used to get 18 mpg on the interstate with the 351W 2v/ C-6 and 3.25 gears.
Truck is alot faster now but sucks the gas
clint

[flyboy2610]

The first question to decide is what you want to do with the truck. if it's going to be a highway cruiser or daily drive, I would get gears in the 3.00-3.25 range.
if it's going to haul or tow, go for 4.11's
For a compromise get 3.50-3.73's.
Just my 2c.