4:11 or 4:56 gears

[Magic1]

Got a 82 Sierra that I'm fixing to put a 300 horse crate motor in with a th350 and a np203 case. I'm gonna regear the front and rear and was wondering which one would be a better all around gear. I'm not gonna be rock crawling or mud bogging with it. Just occasional trips off road. Any help is appreciated since I don't have overdrive and don't want to be taching 3500 rpm going down the freeway. I'm running 35/12.50s. Pretty sure it's got 3:73 now but not positive.

[VileZambonie]

What's the objective? What are you trying to improve?

[Magic1]

Trying to help the "torque" factor. It is severely lacking rite now although it may be from the motor in it now being on its death bed. Just want to have a little more torque out of it and take some stress off the drivetrain. But never having messed around with gears I don't want to go to the trouble and expense of regearing it just to find out that its way too low.

[zieg85]

If you are lacking torque right now with 3.73 gears, 4.11 or 4.56 will help but you will take a "on its death bed motor" and grenade it due to high rpms.  Put your new engine in and see where you are.  My $.02

[Magic1]

If you are lacking torque right now with 3.73 gears, 4.11 or 4.56 will help but you will take a "on its death bed motor" and grenade it due to high rpms.  Put your new engine in and see where you are.  My $.02

Trust me. I'm not going anywhere in that thing until the engine is swapped. I wait for it to spit the crank out everytim I start it up to move it from my driveway to my garage! Lol. That may be my best bet. Just to wait and see how it is after the swap. I just wanted to fish around after opinions about which would be a better gear ratio cause I'm sure I'm gonna change em.

[zieg85]

The extended cab pictured in my profile has 4.56 out back.  It is screaming at 55, I can't stand driving it.  I wish I had 3.73 or numerically lower gears.  On the plus side it will pull a house not that I even have a hitch on it or haul anything... 

[westsidek20]

The right answer is very complicated, you have to put in many factors, general use, tire size, transmission, weight of the vehicle, It has to do with your cam setup also, the rpm working range, and how fast you think you will go. 
Now without any info or knowledge about it, most truck/jeep semi off road vehicles go for 4.56, I've been thinking about this also and a couple of guys I know go up to 4.88 with the kind of tires you are running, then again they use those vehicles on the trail.

When do you think you will do the swap?

[Magic1]

Hope to have everything done by January. Finishing up the wiring now. Then on to the motor then the gears and tcase and finally the body. Can't finish this thing soon enough. I've had it since last October. Been working on it on and off ever since when I get the money. Looking forward to just firing it up and takin off. It's been way more than I bargained for when I got it!

[VileZambonie]

You should verify the ratio you currently have. Tune the engine and play with the timing. That's a good start

[CruzinHigh]

The extended cab pictured in my profile has 4.56 out back.  It is screaming at 55, I can't stand driving it.  I wish I had 3.73 or numerically lower gears.  On the plus side it will pull a house not that I even have a hitch on it or haul anything... 

Hey Zieg -  You guys should swap gears!      (That is assuming you've both got the same axle!)

[clay7]

i'm running 3.73's with a th400 and 35's and my ratio is great.cruises nice at 55mph,got good torque for a decently stock motor and it still hits 110 mph lol (bad idea i know)

[pholliday1]

Magic, My last  truck had 35's had 4.56's had overdrive the motor only made about 230hp plenty of torque "feeling", cruising rpms at 75mph was a little steep(you could tell it was revin pretty good) 4:11 will have better highway manners,especially with no O.D. and increasing hp sorta/ kinda is like having lower gears(numerically higher). After regearing several axles myself i can tell you Vile's advice is spot on. My current truck is geared with 5:38's and 40 inch rubber with a stock TBI 350 and the truck is very "nimble" feeling when you drive it. My point is, its a double edged sword lower gears can turn an under powered truck into a hero however if the horse power is there your need to regear goes away, and its a major exspense to regear.