2007 Nbs 4.8l For Towing

sambuhler · December 22, 2008

I have a 2007 NBS Chevy Silverado 4.8L WT 2WD Ext Cab Std Bed with factory tow package. Unfortunately, I have the 3.23 rear axle ratio which on the NBS puts a max tow rating at 4700 lbs. It seemed as though the 2007 Classics and older models were able to handle about 1,000 lbs more even with the 3.23 rear axle ratio. I currently pull our camper with my wife's 2007 Nissan Armada, but the lease will be up in less than a year and don't know if I will purchase another big vehicle at that time.

The camper is approximately 5500-6000 lbs loaded. I have been told by some shops that what I have will pull it fine. Online I have been reading that I really need to have a rear axle ratio of 3.73 or 4.10. With the 3.73 the tow rating is pushed to 6700 lbs. There does not seem to be anything out for 4.10 unless it is a 4WD. I have been told that the gm parts to get the job done are extremely expensive ($1,200 just for the parts).

My question to the experts .... What part #s are actually needed to complete this job? What do you recommend - tow as is? upgrade to 3.73 or 4.10? Unfortunately, trade-in values have tanked on these vehicles, so unloading it does not seem to be an option.

Thoughts

jrrod2004 · December 22, 2008

I have a 2007 NBS Chevy Silverado 4.8L WT 2WD Ext Cab Std Bed with factory tow package. Unfortunately, I have the 3.23 rear axle ratio which on the NBS puts a max tow rating at 4700 lbs. It seemed as though the 2007 Classics and older models were able to handle about 1,000 lbs more even with the 3.23 rear axle ratio. I currently pull our camper with my wife's 2007 Nissan Armada, but the lease will be up in less than a year and don't know if I will purchase another big vehicle at that time.

The camper is approximately 5500-6000 lbs loaded. I have been told by some shops that what I have will pull it fine. Online I have been reading that I really need to have a rear axle ratio of 3.73 or 4.10. With the 3.73 the tow rating is pushed to 6700 lbs. There does not seem to be anything out for 4.10 unless it is a 4WD. I have been told that the gm parts to get the job done are extremely expensive ($1,200 just for the parts).

My question to the experts .... What part #s are actually needed to complete this job? What do you recommend - tow as is? upgrade to 3.73 or 4.10? Unfortunately, trade-in values have tanked on these vehicles, so unloading it does not seem to be an option.

Thoughts

since you have a work truck, you would really want to go with the 4.10s. I do not consider myself an expert on the matter, but since you have the WT package, changing the rear end will definitely help. It will boost your city mileage just a little but you will pay for it on the highway (mileage loss). I would go aftermarket and have a shop do it for you if you have never built a rear end before. It will be pricey (ranging from $1500.00 to $3500.00 depending on part quality and total labor required.) I would plan on saving up $2000.00 for the complete job (that is what I was quoted to replace my 3.23s with 4.10s).

wtbrowne · December 22, 2008

I don't think towing that heavy of a trailer with your setup will be a pleasurable experience and the truck will really have to work hard on hills. The cheapest way out is to change the gear ratio to 3.73 or 4.10. The 4.10 might be too low if you don't tow often. A 4.10 rear end can really kill fuel mileage.

66nova · December 22, 2008

Sorry must be a double post. I posted on the other one. Good luck.

Will your truck handle it? Probably fine. Will it be a pleasurable experience? I highly doubt it.

If you tow a lot, I would say get the 4.10's. If you don't tow but a couple time a year, the 3.73's should be fine. I don't know any of the part numbers you will need, but I know you can get it done MUCH cheaper than $1200 at about any other shop besides the dealer. You don't need much as far as parts...gear set, maybe a gasket(not sure if these new rear ends use gaskets or silicon) and some rear end grease.

If it were me, here is what I would do. I would pick the gears I needed (based on towing frequency), have a rear end shop install them, then I would email Justin at Blackbear performance for a tune and he will recalibrate you speedo for the new gears. I personally would probably go with 4.10s since the 4.8s like rpm.

Good luck and keep us informed.

Welcome to the site and we need pictures.

J-man67 · December 22, 2008

If its a once or twice a year thing, 3.73's will be fine. If its more then that, I would just go with the 4.10's. Do not buy them from the dealer or have them installed there. They will RIP you off. Since you have a 2wd, I bet you can get the new gears, master install kit, and INSTALL for about 600-1000 easy.

onac255 · December 22, 2008

If its a once or twice a year thing, 3.73's will be fine. If its more then that, I would just go with the 4.10's. Do not buy them from the dealer or have them installed there. They will RIP you off. Since you have a 2wd, I bet you can get the new gears, master install kit, and INSTALL for about 600-1000 easy.

Yeah one set of gears should run you about 250 to 300. Parts and labor should be less than 900 bucks.

BuckFeverZ · December 22, 2008

You can get aftermarket gears for about 1/2 the price and are just as good if not better.

04silverado1500 · December 22, 2008

well alot of guys just say oh yeah get the 4.10s it will pull like a dream! i say otherwise. i think the gears you choose have alot to do with how often you tow and what speed you tow at. i love my 3.73s and it tows nice down the road. so my question to you is how much do you care about highway milesage when your unloaded and what speed/terrain will you tow in?