We've got to spread the love around so that's why we have all those 350 SBC in Fords and then all the 8" Ford rear axles in the Chevies. Nature loves a balance. Well, it seems I'm considering this particular Chevy truck with a Ford axle described as a 280:1 "Single Track". I assume that means it's an open diff, no anti-slip (true?) But I haven't been able to confirm that searching online. Also, I find lots of mentions of a 279 ratio but hardly anything about a 280. So has somebody just rounded up or is there such a beast? Please jump in with opinions on the ratio. I am inexperienced with anything that high (or that low numerically). I won't be racing but I also won't be long tripping but maybe once a year, so figure mostly around town.
My 8" out of a Maverick was a 2.79. One wheel peel. Now a 3.80 2 stripe. Really depends on a lot of things. My t coupe weighs about 2600. Tires are 28" tall. I have a 700 r4 trans with a 350 SBC. Pretty standard stuff. With the 2.79 gears, you could not get it into 4th gear 'til about 50 mph. I drove it in 3rd all the time except on highways. It worked pretty well. Then I put the 3.80's in it. I really like the ratio even on the interstates. Just put it 4th and leave it. Try the Wallace Racing Calculators. They have a good one for choosing gear ratios.
Sounds like somebody just rounded up, 2.79 was a common 8" and 9" ratio. Had several of them, not a performance ratio, just a good daily driver type. Never seen a Ford Trac- Loc on less than a 3.55 from the factory, although it probably was an option, I've never ran into one.
I have a 2:75 in my 48. That is a great hiway gear but it is a slug around town. So IMO if you are mostly around town you won't be happy with it.
I think Ford 'rounded' the numbers to differentiate between the 8" and the 9". And I've seen a trac-loc in a 3.25 rear, it all depends on how the car was optioned.
I used a 65 Mustang 8" rear in my 32 Nash that has the low horse stock engine but needed a better gear than the former stock Nash rear with 4.78. So I ordered a "3.80" R&P set on ebay and when it arrived, it was marked Richmond on the box and also marked as"3.80". It's in the car so I can't give the teeth counts. I forgot what they were.
I believe there is a difference between a 2.79 and a 2.80 gear. My '65 Mustang originally had a 2.80 gear, but I replaced the third member with a later one (from a '68, I believe) that had a 2.79 gear (my original ring gear had a chipped tooth). I just did a little quick research, and from what I can find (it's been a long time, like 20 years, since I swapped gears in that car), the 2.79 has 39/14 teeth, and the 2.80 has 42/15. Who knows why they changed?...Ford often did things like that.
yes, there is a 8" 2:79 & a 2:80 gear ratio - importance is when applied to motor & transmission being used / height of rear tires / how vehicle will be used - had a OT '66 Ford Fairlane GT with mild upgraded 390/close ratio 4 speed/2:79 stock factory 9" rear - a slug from a dead stop - at 70mph would down shift into 2nd and it would fly - loved to be at 80mph and more - yes, needed lower rear gear trac-lock
You guys are super with the great answers. I was going to mention the truck has the 350/3-speed trans in my opening post, but it slipped my mind. I don't know what bolt pattern is on the axles, studs, and wheels, so............ If I want to keep everything same-same, can I simply pop in an anti-slip with a different ratio into the shell of the diff? Or are we talking more parts than that?
Yeah, Fords are easy. Drop the chunk and replace it. All 8” and a lot of 9’ are all the same 28 spline axles. You can buy a complete chunk with ratio of your choice and Traclok ready to install about as cheap as buying the gears and tracloc separate. Poor mans quick change, lol!
Having a SBC in your Ford in the 50s was like having a dropped axle in the 40s. It was the thing! If you are old enough you know what I mean. The golden age.
I put a 9" under both my '34 Ford Sedan with 3.50 Gear ratio (SBC/Turbo 350) and my '49 For PU (390 FE/C6) with 3.25 gear ratio. One was a Speedway Third Member, one was a Currie Third Member, don't remember which is which. After driving them both, I wish I would have went with the 3:70 Gear Ratio for the '34, and I should've put a 3.50 in the '49. The size of the tires really makes the difference.
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