Changing gear ratios...

[PhoenixZorn]

LMC Truck catalogue has me worried now... I have a D44 front and a 12-bolt posi rear end in my Blazer, and I found it has 3.08:1 gearing. Now, with 33" tires, this is all fine and dandy, I run at fairly low RPMs on the highway with my TH350, but eventually plan on swapping out my SM465. I also plan for a future 35" tire upgrade, so the 3.08 gearing will be somewhat lacking. I would like to go with 3.73s or 4.11s, but its my understanding from reading the catalogue that if I do that swap, I need to get a new rear differential case as well as the new ring and pinion set.

Can anyone shine some light on this subject?

 

[mikey_d05]

cases? no

carriers? yes

Junkyard carriers for 3.73's shouldn't be all that hard to find.

 

[PhoenixZorn]

am I going to be able to find the a carrier that had posi though? or doesn't it matter...

 

[89GMCSuburban]

Doesn't matter if it's posi or not. Posi and non posi carriers are the same externally in relation to R&P mounting.

 

[4xcrazy]

why not just go with thick gears?

 

[trailblazr81]

Even better get a Detroit!!!

 

[Executioner]

Which Posi do you have ?
Eaton Gov-lock maybe.