Rear gear ratio

[383bee]

69 bee 383 guess you would call mild build. .30 over not sure on cam.750 carb.727 trans.3.23 rear.i think it's a little doggy on the low end.thinking of going to either 3.55 or 3.73.dont do a whole lot of hiway driving but I do want to drive 70 or so from time to time.afraid i won't feel enough difference with the 3.55.looking for any opinions on either gear?just want a little more fun from the lights.thanks,David.

[4264door]

I'd go with either the 3:73 or better yet 3:91. The 3:91 will awaken the torque you have built into that engine combination and give 1/2 decent fuel mileage and still have plenty of 'legs' on the freeway. Your carb is a bit large for a 383 without knowing the cam specs I would tend to down size to a 650 Holley with vacuum secondarys but that is a topic for another thread, for now you are concerned with rear gear ratios.

[383bee]

Thanks for the opinion.leaning toward the 3.73.i do want some high end left without a screaming motor when I do get on the hiway.from what I could find out about the cam it's a comp magnum 280 grind if that makes any sense?almost forgot running 275 60 15 rears

[67440Dodge]

3.91 gears 255/60/15 tires doing 65mph (just to give you an idea of RPM's)

1420

[ws27]

Before you change gears, try what 426 said. Get a smaller carb. That might waken it up enough with out all the other repercussions.

[383bee]

Thanks guys.i did have a 600 cfm on it when I got the car.really don't see much difference between the two. Just a little disappointed in the low end.just feels like something's not there that should be

[ws27]

If you already tried it, then gears are your next choice. Or more cubic inches, but changing the gears is much easier and cheaper. Let us know how you make out.

[Sedanman67]

Try a torque converter swap first.

[Hibbing_Coronet_500]

Not to go off base here. Has the car been properly tuned?
I have a 383 with factory cast dual plane intake and edlbrock 1406 carb.
I set my ignition timing at 38 degrees at 2500 rpm.
I also made sure my reluctor air gap was set at .008. Good quality cap, rotor and wires. Plugs at .36 with blaster 2 coil.
I set carb mixture screws using a vacuum gauge.
I have. 2:94 open gear on my Coronet and I like my performance for street use..

[thebankerstoy]

Try a torque converter swap first.

An excellent suggestion by Paul, as installing a new gear ratio without addressing the torque converter would decrease the effect you're looking for from the new gear ratio. I would also say that if you're going to be driving your car on the freeway much, stay with a more forgiving 3.55 gear ratio along with a Sure-Grip unit, rather than the 3.73, or 3.91 options.

With that said, I absolutely LOVE the 3.91 Sure-Grip equipped 8.75 in my 66 Coronet 500, both on the street and on the drag strip and I normally run a 3.91 gear ratio on all of my big block powered Mopars, but along with the 3.91 gear ratio, I also run well built 440 engines, full manual, reverse shift pattern 727 automatic transmissions and higher stall aftermarket torque converters, so the whole drive train package is set up to work well together, but then again my cars aren't driven on the freeways much, so I don't have the concerns that you do.

The key in my humble opinion for anyone building and driving a mild, to highly modified Muscle car, is to build a complete drive train and suspension package that works well together to achieve what the owner wants to do with the car most of the time, rather than looking at individual parts to band-aid an isolated problem.

Richard