Posi Gear ratio recommendation needed

Jan 27, 2004 11 Replies
65 FB 289 A Code w/C4 auto... stock 8" rear end, going to 8" posi and need a recommendation for gear ration. Use will be daily driver, road trips (local to cross country), with a wee bit o' th' stop light action when the urge strikes; ) So, looking for a good cross between some snap and good gas milage (relative to my foot on the pedal).

Appreciate the help. V'ger



1965 Fastback 2+2 Burgundy w/ Black A Code 4 spd
1966 Fastback 2+2 White w/Red C Code Auto

Another option would be a low gear set for the transmission. It will take the stock 2.46/1.46/1.00 ratios to 2.84/1.54/1.00. That would make a 3.25 gear ratio feel like 3.75 in first and 3.43 in second while not losing anything in drive to help keep the gas mileage. Add a mild converter while you have the tranny out and you'll have a nice punch off the line while not giving up any cruising rpm.

MadDAWG

Keep in mind used "speed parts" (the traction-loc) for the 8" now command a lot more money then the much more plentiful 9" parts...

What you're looking for is a nice comprimise. I have a 3.00 in mine (302/C4), and that's pretty good for cruising, but not nearly as quick as I would like (but then, what is?). But when I rebuild the rear this year I'll switch to a 3.50. 3.75 will make it jump off the line really well, but cruising down the highway will be a bit of a stretch.

V'ger

1965 Fastback 2+2 Burgundy w/ Black A Code 4 spd 1966 Fastback 2+2 White w/Red C Code Auto

DAMN!!!!! maybe i should sell the one I have sitting on my shelf collecting dust. IIRC I got a set of 3.25s for an 8" also.

MadDAWG

Is that just the Traction Loc, or the complete rear-end? You can buy a brand new Detroit Locker for about $425, and that is twice as sturdy as any Traction Loc. FYI: "posi" is a GM trademarked term, and even though we know what you are saying, it technically does not apply to a Ford, unless you are putting a GM rear-end into your Ford... BTW I just bought a big FoMoCo complete drum to drum 4.10 locking rear-end out of a '92 1-ton Ford Truck for $600. Yes it's going into a truck :-)

Just the TracLok.... 3.25? How much?

yeah, I know the dif between posi and trak... just been tlk>65 FB 289 A Code w/C4 auto... stock 8" rear end, going to 8" posi and

V'ger

1965 Fastback 2+2 Burgundy w/ Black A Code 4 spd 1966 Fastback 2+2 White w/Red C Code Auto

You talking to me?

if so email me

MadDAWG

V'ger

1965 Fastback 2+2 Burgundy w/ Black A Code 4 spd 1966 Fastback 2+2 White w/Red C Code Auto

That's intiguing! Tell me more.

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