Hey Aaron, yeah I'm from Corbin.

 

It's a 3.92 (divide bottom number into top number). And for a 1952 truck, that's probably a dana 44. It will be stamped with a "44" on the rear housing just outside the cover plate at about the 4:00 position.

 

My 50 F-1 had a 302 with a C6 in front of a stock Dana 41 with a 3.73 ratio before I tore it apart. It wasn't too bad at all. It would run 70 mph pretty easily.

 

I have been out in the garage working on the truck and found on the plate on the inside of the glove box that it is a 3.92 rear end.

I believe I'll use the 9 inch rear I've bought with the 2:75 ratio and see how that works for a little while. Thanks guys for all the information!

Have a good one

Jon Preston

 

I have a 9" I just put in my '52, with flathead V8 and LD 3-sp. With a 3.25 gearset, it's a dog off the line and pulling 3rd on a hill is barely adequate below 50 mph. With a 2.75 you'll likely burn up your clutch in no time. I'm switching to 3.50's.

 

It all depends on what you want your cruising RPM to be. To figure that your trans is 1 to 1 in third and like stated, you need to know your tire diameter. There are several calculators on the web that allow you to put in your numbers and it will spit the info you need to know for picking your diff ratio. My truck runs 27" tires with 3.89 gears and a T-5 with approx .70 top gear, cruises at 70 mph about 2100 rpm. 2.75 gears in a truck are going to be doggy and depending on your tire size might put as low as 1500 rpm at cruising. Most trucks run taller tire which will hurt you for power and cruising.

 

Are you running a flathead? Is your T5 out of an S-10? If so, I'm curious if you even use 1st? The T5 I have (not installed) has a 4.03 1st, seems useful only for pulling stumps.

Ironically, I also own a '98 S-10 with the 4-banger and 5-sp. It is the later Aisin 5-sp, which has a little shorter 5th (.83), and it has a 4.10 rear axle. The S-10 weighs 150 lbs more than my F-1, has 20 more HP, and runs tires that are just a little shorter. 1st gear in it will get me across an intersection, and that's about it. The biggest difference is the S-10 is far more aerodynamic, above 50 my F-1 is pushing an awful lot of air.

 

Hello,

The more I think about it, I may just keep the stock rearend in my truck and see what I'm comfortable with, if it's not what I want I can always change it. The stock gears are 3.92 and so far the information I have gathered from several sources are varying quite a bit. I'm going to do some more research before my ultimate decision.

Thanks again.

 

i have a 3.0 rearend behind a c4 off my 239 flat 8 i took it down the interstate today and she was running 80 and i was barely touching the gas
im thinking of puting the stock rearend back in but i have all new brakes on the 9

 

Ross,
My T-5 is a '92 Mustang unit and I am running a 306 (.040 over 302) with a lot of work into it. 4.03 is a very steep first gear, mine is a 3.27 and that is almost to much. If I decide to go through it I might throw an aftermarket gear set at it to bring it down to 2.93 (?) first.

 

Thanks Dave, good info!

 

So.... Is that one of those arrangements where you have to make an appointment for a freeway on ramp ??

 

Ok, so after some careful decisions, I've decided that I no longer am going to go with a c4 transmission, instead I want to use a manual 5 speed. Any recommendations on what would be best to put behind my 302 with a 9 inch rearend 2:75 gear ratio?

All suggestions and help are greatly appreciated!

Thanks again,

Jon

 

I think you need to re-assess your approach. Figure out what speed/rpm combination you want to end up with first. After that see what the ratios are for the available transmissions, then determine what your rear end ratio should be. With your current approach you'll be hunting for a very specific transmission that might be hard to find. You can change the gears in your 9" for a relatively low price.
Dan

 

You can't go wrong with a T-5 behind a SBF. If you go with a Ford T-5 make sure to get a World Class T-5 and not an early non-world class trans. Also be careful about the input shaft length, they became longer in "93, they work but you need to make sure you run the correct year bellhousing so that everything is the right length. Be careful and make sure it is a SB trans and not the V-6 of 4 cyl. version, not as strong and wrong (bad) first gear ratio for the SB. You can buy one new at several places including Summit racing, and when compared to the cost of rebuilding one and the strength increase of the new ones, not a bad deal.