Best Gear suggestions for 4.8L, 4L60E

[C91]

I have a 1966 fleetside shortbox C10 with a 4.8L, 373s, cammed and performance tuned. She goes pretty good but im looking for moreo ut of the hole. Anyone else out there with similar setups ? Whats the best gear ratio? and how did you choose those gears and name brand? I have a 12 bolt Chevrolet rear end and im looking for any advice or guidance

[luvbowties]

Originally Posted by C91

I have a 1966 fleetside shortbox C10 with a 4.8L, 373s, cammed and performance tuned. She goes pretty good but im looking for moreo ut of the hole. Anyone else out there with similar setups ? Whats the best gear ratio? and how did you choose those gears and name brand? I have a 12 bolt Chevrolet rear end and im looking for any advice or guidance

(wrong post-to)

[luvbowties]

Originally Posted by C91

I have a 1966 fleetside shortbox C10 with a 4.8L, 373s, cammed and performance tuned. She goes pretty good but im looking for moreo ut of the hole. Anyone else out there with similar setups ? Whats the best gear ratio? and how did you choose those gears and name brand? I have a 12 bolt Chevrolet rear end and im looking for any advice or guidance

(wrong post-to)

[C91]

what does wrong post-to mean ? just trying to get some advice. thanks.

[Captainfab]

What gear ratio do you have now? What size rear tires? Typically a 3.73 ratio works well with an OD trans. Does the cam in your engine need a stall converter and do you have it installed?

[luvbowties]

Originally Posted by C91

what does wrong post-to mean ? just trying to get some advice. thanks.

I erred in posting responses to wrong question--sorry.
Sam

[Clyde65]

I have the same set up as you. I have 29" tires with 3.73 gears in my 12 bolt. My truck does fine (for me, not a hot rod just basically stock LSx) out of the hole but for you maybe a lower ratio would get you what you need, you would need a 4.10 maybe?

[Blessed66]

For what its worth, if you're looking for launch without sacrificing cruise speed (what a lower gear will do), you should consider a different torque converter.

I had an LT1/4L60E years ago that had a 2800rpm stall. Made all the difference in the world drag racing. Still had 3.73 rear gears like you. Granted, it was a Camaro so its not quite the same but the better converter made a world of difference. Before you look into a new rear gear, I'd look into a better converter to let you get off the line closer to that engines optimal power band. You won't be sacrificing as much on the road as a 4.10 would do for cruising. Just depends exactly what you want.

[C91]

Thanks guys. All great advice. To clarify, I have 4L60e tranny which has overdrive, I have a 3200 circle D stall converter and 373s. The truck weights about 3500 lbs. I'm just looking for any advice on gearing and specifically name brands of gears. I'm leaning towards 410s with posi for my 12 bolts but what's some good company's to buy gears from ? Thanks for the advice boys !
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[Captainfab]

From what I have heard, Yukon Gear makes some of the best quality gears.

[C91]

Oh also forgot to mention I have a comp cam 212/218 with the back tire height of 28.75"
Posted via Mobile Device

[Clyde65]

My gears are from Yukon as well. I bought mine from Summit.

Is that the stall the cam folks suggested?

[C91]

Yes Clyde the 212/218 is what they recommended. I researched it for quite sometime. If you go anymore aggressive than 212/218 you start to make it even more of a dog out of the hole and with this mild cam i didn't have to do the springs.

Anyone else out here have an LS and have an optimal gear setup and company?

Thanks

[DLW]

That cam is pretty tame, who's cam is it? What is the lift? What is the LSA?.

Optimal depends on what you want. 4.10's is good at the strip, not as good on the freeway. 3.73's is a happy medium. 3200 stall should be enough,

Is your out of the hole take off bad now? You drag race and looking for better 60' times? I don't think the 4.10's will make that big of a difference. A looser stall might help if that Circle -D is tight, but at some point day to day driving will get annoying with a loose/high stall. Personally, I like the 3.73 gears coupled with that 3200 stall you have. You might just be out of motor.

I to am using Yukon at the moment.

[PGSigns]

All we ever ran for gears in the racecars was Richmond. For more out of the hole I would look into the tune up that is in the ECM first.
Jimmy

[corvettejim1968]

3:73 is a great gear it pulls pretty hard and you can drive on the freeway. thats what i have in both of my trucks and the Corvette I had.

[aggie91]

We have an LS set up in my '85. About the same weight as what you have.

Mine is a 5.3/4L60e combo with a smaller stall (about 2400-2600), mild tune on the ecm to optimize my stock cam, cold air intake and headers. We run a 28.68" tall rear tire. We have run it with 2.73 gears and 4.10 gears. After having and driving both set ups, I would really like to do 3.73's in ours. The 4.10's really woke it up out of the hole but it did sacrifice top end and highway cruising. We have an Eaton Posi and Richmond Gears. Yukon sell good stuff and pricing is reasonable.

Future plans include a turbo set up, so at that time we will most likely go to 3.42 gears in the rear with a new carrier since those require a 3 series carrier versus the 4 series we have now.

FWW, I plan a 4.8/4L60e combo for my '65 when I get back on it. It will be a DD for a good bit, I will do a similar tune and converter combo with 3.73 gears since I have a 12 bolt with stock 3.73's already. I will most likely add a locker or limited slip carrier also.

[C91]

Thanks for the advice guys. I'm leaning towards the yukon 410s with posi, going to get a quite tomorrow !!! When it comes to tuning I have a guy and its tuned to fly hopefully these gears wake her up and yes the cam is mild but man does it sound mean. The cam is 212/218 with an LSA of 114 which is optimal for a supercharger/turbo setup down the road.

Any other recommendations to get this little truck flying would be appreciated

[Tilt]

Just to give you an idea of cost, I had PYLE BROS in Baytown quote me a rear end with 3.73 Yukon gears and LSD at a little over $1600 OTD.

[Andy4639]

6.0 with 4L80E combo. stock everything straight out of the heavy duty into my 71 with 4:10 gear set. Mine runs about 2400-2600 RPM's at 70 MPH.
At 60 MPH it's about 1800 RPM's.
Gets about 16MPG. That's running the AC pretty much all the time also.

[homemade87]

Originally Posted by C91

Thanks for the advice guys. I'm leaning towards the yukon 410s with posi, going to get a quite tomorrow !!! When it comes to tuning I have a guy and its tuned to fly hopefully these gears wake her up and yes the cam is mild but man does it sound mean. The cam is 212/218 with an LSA of 114 which is optimal for a supercharger/turbo setup down the road.

Any other recommendations to get this little truck flying would be appreciated

If you have not had it on a dyno to tune it you could be leaving a lot on the table . Ask me how I know . I could not get my truck to leave from a stop or low speed . I finally took it to the dyno after a couple tuners looked at it ( waste of money ) . No way for a street tune to get you where you need to be . My fuel curve was way off down low . After three pulls on the dyno I gained almost 100ft lbs torque below 4500rpm . What a difference . I do have a 6.0 but this applies to every engine combo .No way to know this unless on the dyno .

Take it to a dyno . You may fine what you need . I wish I had done this first before wasting time and money on street tunes . Don't get me wrong . Most tuners do a great job and get it running pretty good . But if wanting to tune for best performance take it to a dyno .

I look at it this way . Its like checking tire pressures with out a pressure gauge .