question on gears

[GhettoPop]

Any of you familiar w/ Dave Isreal 4.31 gears? Are these common?

[BIG MIKE]

never heard of dave isreal, but the 4.31 are some low gears. 55-60 the engine would be revving 4000-4500 without an overdrive.

[GhettoPop]

Yeah they are high. With the 3 speed slap stick, 1st gear is insane! tires spin almost too easy, 2nd gear is nice though. next time i'm on the highway i will post what my rpm's are in 3rd gear around 55-60 mph.

[johnrez]

Not sure what you're planning on using the car for, but anything in the 4's is serious draggin'.  I've got a 340 e body with .474 lift 280 deg purple cam, 10:1 pistons, ported, polished, M1 Mopar manifold, balanced internally, 670 Holley carb, MSD ignition system, 727 trans with kevlar clutches, valve body regulator change for full clamp load to the clutches for capacity, shift kit, 170K stall convertor, 3.91 Richmond gear, and Auburn grip in the 8 3/4 " rear....  Lemme tell you, I'm thinkin' of movin' down to a 3.23 ratio for a cruiser...  The 3.91 and converter combo makes it tuff to even hook up in first!  High revs on the freeway...  But gets there quick!  My recommendation is build your engine for good low end torque.  Then you don't need to rely on gear multiplication for the torque, and won't be stuck with such a high ratio on the freeways.....  Of course, if you're tubbed with slicks, wheelie bars, and a monster engine for the 1/8 or 1/4 mile....  I know a guy running a ratio in the 5's!

[jterp]

gearing depends on the torque curve of the engine, if you make power through 6500 then you can drag race well with a 4:31 gear-- if your peak torque is at 5100 like in the 360 crate motor (my car) then a lower gear is much better. a 3.91 is still pretty steep for long highway driving--- a 3.23 is great for the highway but you might not get the launch that you want... My fav. is the 3.55  perfect compromise.

[GhettoPop]

So has anyone heard of Dave Isreal gears? Also, can someone figure out the exact gear ratio w/o taking the rear end cover off? If not whats the eaisest way?

[Grancoupe]

The easiest way of "estimating" (key word) is marking the driveshaft and the tire. Rotate the tire once and count the number of rotations the driveshaft makes. Of course you'll have to estimate the last turn. Also, I'm running a set of 4.56's and not much of a problem doing it. Its the tire height that is also a factor. I have a set of 27 inch tires back there so its not that bad. 4000 at 65 in a big block. Not for weak hearts. But if you trust what ya build, then have fun with it!
Not sure about the Dave Isreal thing though. I run Richmond Gears. They seem to have the least amount of problems fitting. Later