Tall gears and 4-speeds
Car is a 73 Duster, mild Magnum 360, 833 trans with V8 gears, I think 26" tires. (225/60R15) Currently has 8.25" with 3.55 gears, and...yeah, that's getting old. Does anyone have actual EXPERIENCE with a 4 speed and 2.76 axle gears in a ~3300lb car? How does it drive?
How does it drive?
Can you be more specific?
with your combo; 65= 2300 rpm which cruises fatastic
But the starter gear of 2.66 x 2.76= 7.34, requires a pretty stout bottom-end. It will require a good bit of slippage to take off briskly. I solved that by installing alloy heads and running the cylinder pressure up to 180 or better. My 360LA then had plenty of bottom-end punch.
You can get a leg up on it by installing the Commando Gear-set which has a 3.09 low. This would make your starter gear, 2.76 x 3.09=8.44, about the same as 3.23 x 2.66=8.59. The 5.9 IIRC comes with an Scr of 9.0 or 9.2 I forget which, but the end result is the same; a mild cam won't kill the bottom end.
But as someone said; your Duster with 3.55s, and 28" tires would cruise at ~65= 2770 compared to the current 2980 with 26s.
but here's the thing; Second gear is 1.92 and with 2.76s, that will get you 44mph at 3000/ 60@4100, compared to your current combo doing 34@3000/ 60=5300, so you can expect your zero to 60 ET to be down a bit. Maybe quite a bit, lol.
I didn't run those gears for long because of that very reason. Eventually I bought a GVod, and now 65=2240 with 3.55s ............
Perhaps, for you, the A833od might be a good solution. With your current 3.55s and 2.76s; it will give you 65=2180, with a starter of 3.09 x 3.55=10.97/same as I run . But Second is a lil far away in it.
here are the ratios; first yours
2.66-1.92-1.40-1.00, next the Commando
3.09-1.92-1.40-1.00, then the overdrive
3.09-1.67-1.00-.73od
Road gears next; first yours with the 3.55s
9.44-6.82-4.97-3.55, (65=2980); followed by what they would be with 2.76s
7.34-5.30-3.86-2.76,
(65=2320); then the overdrive with 3.55s
10.97-
5.93-3.55-2.59od
(65=2180); And then the Commando with 3.55s to 3.23s, then 2.94s
10.97-
6.82-4.97-3.55,
(65=2980)
9.98-
6.20-4.52-3.23,
(65=2700)
9.08-5.64-4.12-2.94, (65=2470)
IMO,
and for a 360/5.9 street car;
Second gear ratios in the hi 6s are pretty good
Second gears in the low 5s are pretty tame.
Second gears from about 5.5 to 6.5 are a good compromise to get a decent cruising gear.
BTW;
those overdrive transmissions can be had pretty affordably. But they do require a fairly wide powerband, which the modest compression 5.9 Magnum should have. IMO I would certainly try one before I would go to 2.76s.