Got done last night around 10 PM - just enough time for a quick spin. I'll be testing them out in a bit

Spiders were GONE on the 3.73's I think between the 4 there were 6 teeth left

Could have reused the 3.73 ring and pinion, but I do alot of hauling, and wanted some more holeshot.

Just found out you cant get 4.10's in a 1/2 ton from the factory - only as low as 3.73's. Kinda wierd - seems like they might have issues? I dunno - the factory gears lasted only 105k. For the last 5k the rear end has been whining, and last weekend at the track finished them off.

But it could be due to the way I baby my truck

 

In the first couple of years of production new body style 99+ you could get a 4.10 option,now you can again on the 05 z71.If the spiders are munched it could be from doing 1 wheel peels around corners.

 

So hows the sotp meter on that 373 to 410 upgrade. I got 373s and tons of tools . A gear swap eould be a cheap mod for me.

 

Well - I just got back from driving it all day - and all I can say is WOW!

We all know the LS1's are screamers, developing all their HP and torque at high RPM's, but I never knew what a difference gears would make. All around driveability is WAY better. The engine is in the torque band around 80% of the time now as before it was more like 50%. Corners are not lagged up like a turbo lag anymore. I was able to bark the tires on a 1-2 shift before, not it'll do it on a 1-2 AND 2-3. The speedo was off a ton - HPP3 fixed that for me.

Mid range accel - nailing the gast at 60 MPH feels like the hand of God comes down and pushes you forward HUGE difference in second gear between 3500 and 5500 rpms. I can only imagine the difference you guys would feel going from a higher gear than my old 3.73's to a 4.10.

Bad - well - at 65 mph it runs around 2200 rpm, and at 85 it's about 2600 - before it was around 1900 at 65 and 2200 at 85. I expected this, and I'm not complaining about it, but keep it in mind for you guys who have DD'rs.

All in all - the fun factor at lights and start stop is worth every penny I'll be towing the trailer this weekend, and give a report on that early next week.

 

Let us know when you get the fronts done. I've done the rear before, and thinking of going with 4.10's now, but I use my 4wd alot, and am not looking forward to swaping the front gears.

 

I'll be doing it this week - I just got done replacing the factory cats with high flow. What a difference. Since the rear end and the exhaust, the truck is like a whole new story.

 

I should have gotten the 4.10's, they were an optoin in 04 also. Your RPM should be only about 10% off sins that is all you changed your gears, so I would double check that.

 

Yeah - my memory could be a bit off - but it is defiantly up into the high torque range on the expressway now cuz the exhaust is in the hum mode, where before it was quiet.

 

So 4.10's will help your passing power? In 03houstonsierra's post he said it got worse.

 

I would think that it would help. Its a lower overall gear ratio.