hey yalll

i got a NBS 04 stx xcab 6.5 w 4x4 2v 4.6 to 2v 5.4
i got 3.55 gears no ls

can i go to a junk yard and pick up a 9.75 3.55 rear w/ LS and bolt it right in???
this way i get a beefed up rear and LS for less than just adding tru trac to the 8.8.

doing gears/ adding posi looks like a PITA

 

so anyone got insight if the 8.8 driveshaft will work? suspension? brakes?

thinking about parking next to a 9.75 and look for any differences

 

edit

 

Other than the driveshaft, it should be a direct swap. Looking at Siklverstate it appears the DS is different between 5.4 and 4.6. I am not 100 percent sure on that though.

 

drive shaft is going to be different i think it matters on the motor size for ds as well... a used rear should have brakes on it atleast thats how we sell ours.

 

What trans are you running?

The only thing I can think of is the drive shaft may be shorter with the 9.75 having a longer snout than the 8.8

 

i am running the 4r70e from the 4.6
i plan on getting the 4r75e when my tranny goes and running the 4r75 TC
my TC is a higher stall then the 5.4 came with

i know* that i can swap trannies with out doing the driveshaft.

i figured there might be something stoppin me
so maybe i get the tape measure out and measure u joint to u joint or maybe just cross reference the D.S. part numbers

 

I would grab the rear and drive shaft at the junk yard. The pumpkin on the 9.75 is bigger so the drive shaft is shorter.

 

what do you mean matters on motor size???

all 4.6 have 8.8 rear and 5.4 got the 9.75 rear
all 4.6 have the 4r70 and 5.4 have the 4r75 trans
i do have a 5.4 now, so the 9.75 seems appropriate

my truck is already frankenstein

i plan on a 4r75 when my trans goes AGAIN and get the tune for the different speed sensor

i dont think tail yoke is different on the 4r75, as its the same housing, but then again i could be wrong

i see some 2005 have an aluminum drive shaft, that would be sweet to find one of those

 

thanks five o, i figured as much. i wonder what a rear and DS is gonna cost

 

driveshaft part numbers

4L34-4602-DD Aluminum SCAB

4L34-4602-FD Steel RCAB

5L34-4602-XC Aluminum SCREW

4L3Z-4602-KB Steel SCREW

 

He's probably thinking that because only the 5fours had the 975. That doesn't matter.

I'm thinking the pinion is longer, so you'll need the shaft ? Not sure, Something has to be... - To accommodate the larger ring gear. Additional length is needed to center with it, right.. Regardless, I'd need to either look up R&P sets and hope for a measurement or get a shaft measurement.

 

yeah that makes cents.

hopefully my local harrys u-pull-it has the 9.75 for a decent price. ill get the rear and and shaft. hopefully not the shaft in the rear. lol

maybe pickup up a holset turbo while im there....

 

I may have been misinformed... my bad motor size shouldnt matter as long as shaft is off a 9.75 rear motor size shouldnt matter...

 

no your right, only 5.4 came with the 9.75, so i need to find a 5.4 truck