4.56 Gears

[Supercharged111]

Also I think 95 was the last year to get 4.10s in a 1/2 ton, even the 2500 6 lug. Im looking for a set for my Yukon, can't find em.

My 4.10 diffs in my 98 came from a TBI truck.

 

[b454rat]

Every 2500 6 lug I run across I look for 4.10s. Never found a set. There is a guy trying to sell a 95 rot box, he took a pic of the RPO codes and says GT5, but wont' sell the axles. I really only want the front, since regearing the rear is $125 for a new set.

 

[L31MaxExpress]

Every 2500 6 lug I run across I look for 4.10s. Never found a set. There is a guy trying to sell a 95 rot box, he took a pic of the RPO codes and says GT5, but wont' sell the axles. I really only want the front, since regearing the rear is $125 for a new set.

Look in the 4.3 2500 trucks.

 

[Wheeler]

Throw a positive displacement supercharger on there! Bit more money but big bang for your buck.

After you posted this, you had me researching... man that really seems like they put out some killer power.. I read a few articles about the 5.3 stock with just adding a procharger for towing & the hp/tq #s were very impressive...

I'll be inquiring about this with the tuning shop I use...

 

[Madscientist]

After you posted this, you had me researching... man that really seems like they put out some killer power.. I read a few articles about the 5.3 stock with just adding a procharger for towing & the hp/tq #s were very impressive...

I'll be inquiring about this with the tuning shop I use...

I have a 5.3 in my truck with the BTR stage 2 truck cam and some bolt ons. It runs extremely well with the 4.56. I do a fair amount of towing and it tows 6500 lbs in OD. I also have a supercharger off of the sts-v 4.4 northstar motor. im doing a fair amount of work to make an intake manifold for it but im not too far away from it.

 

[b454rat]

I looked at those for the NV4500s and still didn't find any. Most had 3.73s, some even had 3.42s. Not a big deal, if DMV doesn't open soon so I can put it on the road, then gonna SAS it. Have 90% of the parts.

 

[cngodfather]

I put 4.56 gears with 35" tires and I love it.

 

[stutaeng]

Look in the 4.3 2500 trucks.

C/K 2500 came with 4.3/4.10? What years were these optioned? I thought C/K 1500s only came with up 3.73? Maybe the GMT-400 SS came with 4.10?

OP, I thought the 383 with 4.56 would have plenty of power. At the end of the day, 7,000 lbs is not a ginormous load. You've already spent a lot of money on upgrades. I would not do a supercharger because you are running a 4L60e. Even though it's rebuilt, they are not known for taking a lot of power, unfortunately.

Maybe a 7.4/4L80e would have enough power for you? Are the 8.1/Allison GMT-900 trucks available in your area? The 2500/3500 trucks are heavier and could pull a heavier load, just don't think they will be much faster, unless towing to the max. Maybe I'm wrong?

 

[98chevy2500SS]

Maybe the GMT-400 SS came with 4.10?

You are correct, 91-93 454SS's came with 4.10's, I believe the 90 454SS was the only year to have 3.73's.

 

[Wheeler]

C/K 2500 came with 4.3/4.10? What years were these optioned? I thought C/K 1500s only came with up 3.73? Maybe the GMT-400 SS came with 4.10?

OP, I thought the 383 with 4.56 would have plenty of power. At the end of the day, 7,000 lbs is not a ginormous load. You've already spent a lot of money on upgrades. I would not do a supercharger because you are running a 4L60e. Even though it's rebuilt, they are not known for taking a lot of power, unfortunately.

Maybe a 7.4/4L80e would have enough power for you? Are the 8.1/Allison GMT-900 trucks available in your area? The 2500/3500 trucks are heavier and could pull a heavier load, just don't think they will be much faster, unless towing to the max. Maybe I'm wrong?

You are correct.. I've spent way more $$ than some will believe... I thought the 383 with 4.56 gears would be a beast.. (295/70/17 Tires too! 33.26") but it's just not what I expected. It does what I want but for the $ spent & how it pulls 7k up small grades in 3rd unlocking just surprised me.. so I want more.. I did keep the stock heads which maybe a hindrance.. I'm not sure. I don't want to go fast, especially now that I have the low gears.. Yes I know the 4L60e is a weak link. Builder told me not to exceed 500hp as that's all it will hold "as per his build"... I only put down 250whp & 322ft/lbs tq. I would like to see some more.. Larger heads & long tubes maybe? Positive Displacement Blower will do trick... I dunno... maybe I should just get a diesel....