Diff ratio

[Sacko7 4]

I have just recently converted my XE from a 6 to the 351 V8. Having drum brakes on the rear I fitted an XR6 rear end so that I could stop. I took the car out for a run and was doing about 2700 revs at 100kmh. Wanting it for a cruiser and not needing it quick off the mark I looked at the diff ratio. I believe what is currently in is a1-345 which would have been coupled to a 4 speed box. I am about to change it to a 2.92 but I have been told that the V8 actually had a 2.77. But I have been told that 2.77 will not go in a Borg Warner housing. I am not unrealistic, I did not convert the car for economy and having a new 650 Holley it will use fuel. But if I can just decrease the revs a little at highway speeds I would be happy. Any idea's welcomed.

Thanks Sacko7

[CHESTNUTXE 7,312]

yes 2.92 does go in,you just need the 2.92 carrier or centre ,the 2.77 did come out with 351 auto,some 302 had 2.92 ,im doing exactly that at the moment,using a late xf ute diff centre and 2.92 gears and retro fitting it into my xe drum brake housing.

[deankxf 20,292]

2 hours ago, Sacko7 said:

I am about to change it to a 2.92 but I have been told that the V8 actually had a 2.77.

 

in My experience most borg warner diff V8s were 2.92 (9" had 2.75) 

there's only 5% difference to them. 

2.92 at 100kmh would be about  2400rpm

2.77 at 100 would be 2300 ish

3.45 XR6 diff you have should be 2850rpm 

3.23 XR8 diff would be about 2650/2700rpm 

 

if you have a ready to fit 2.92 diff, just chuck it in,

2.77 isn't enough difference to be worried about even on a 6cyl 99% of the time. 

 

[Thom 6,651]

3.08 is the standard 6 cyl ratio for e series falcons, probably easiest way would be to swap the lsd out of the 3.45 in it and then put the whole 3.08 diff in

[Underpants1967 12]

2.92 will be fine for cruising. I have XC wagon with 351 FMX and V8 LSD 2.92 disc rear from XD ute/wagon. 100k is a bit over 2000 rpm depending on tyre height.