9” is overkill though relatively accessible. They are big and heavy. Shortened Borg Warner are easily capable of handling abuse. Banjo are easy but getting scarcer and dearer. They handle sensible use well in a lighter car such as FB EK.
FB ute fixer upper, EK van on rotisserie
Thanks mate , the car won't be driven hard so will just stay with the banjo .
If you stick with a stock diff there are plenty of spares around if you do happen to do an axle, if you go Torana diff to get more dish on your wheels pretty sure there are aftermarket axles available for them.
I started with nothing and still have most of it left.
Foundation member #61 of FB/EK Holden club of W.A.
Blacky wrote: Sat Feb 08, 2025 7:50 pm
A 9" is overkill unless you are planning on a 400+hp donk and sticky tyres
Agree. The wagon runs a shortened BW78, with 400hp at the crank. It lives on abuse. It snapped the original 28-spline axles, but I cannot kill the replacement 31-spline units.
Cheers,
Harv
327 Chev EK wagon, original EK ute for Number 1 Daughter, an FB sedan meth monster project and a BB/MD grey motored FED.
My two cents I've shortened two Commodore diffs now one for my FC Sedan and one for my EK Ute they are a good diff, have good rear disc brakes and can get LSD however because they are fairly easy to shorten they are becoming dearer.
If you were to go this way you make sure that you have the rims you are going to use and shorten the diff to the rims.
Neil's 2 cents
Member of WA FB/EK Car Club
Frankenstein EK V6 Ute
The Reverend FB Station Wagon Project
1950's Commer Light Truck (2.5 Ton)
Cheers for the input all , I pulled the diff out today we slapped it in to get it home from the panel shop. Pulled the centre and axles intending to to clean up reseal extra.
It has a 3.08 centre and the teeth don't look the best. The final set up will be a triple webber red with celica 5 speed I'm thinking this ratio may be a bit to tall.
I'd value some recommendations on a ratio suggestion the car will see some hiway kms but not excessive. Would still love some get up and boogie but also reasonably drivable both round town and hiway ???
Did up the Hr front calipers yesterday , don't those piston boots bring out some colourful language .
i had mild 202 with 5 speed had 3.36 and was fine on the highway i toyed with trying a 3.55 but never did i rekon still would have been fine i did put a 3.08 when we went to red center nats and was also great
sometimes yor just better off shitting in yor hands and clapping
3.08:1 would be good with the overdrive at 100. Depends how tall your rear tyres and how much toe off the line you want. With Webers makes me think you want to rev it, rather than hit the highway, and not worried about fuel economy. A nice compromise would be 3.36:1.
FB ute fixer upper, EK van on rotisserie
getting my FB ute on the road
EK van on rotisserie
1:3.36 diff on my 186 powered ute with Celica 5 speed. 2550rpm in 4th at 100km/h and 2150rpm or so in 5th. Plenty skippy in first, 2nd and 3rd. Happily sits in 5th on most hills too. 13inch wheels with 185.R80.
Wasn't so happy in first gear with 4speed M20, but pretty sure it was a fancy M20 with low ratio first.
Brett027 wrote: Mon Feb 24, 2025 10:37 am
1:3.36 diff on my 186 powered ute with Celica 5 speed. 2550rpm in 4th at 100km/h and 2150rpm or so in 5th. Plenty skippy in first, 2nd and 3rd. Happily sits in 5th on most hills too. 13inch wheels with 185.R80.
Wasn't so happy in first gear with 4speed M20, but pretty sure it was a fancy M20 with low ratio first.
If that gearbox had a super tall first gear it was most likely an M21 - could be worth lots of money to a Torana restorer.
I started with nothing and still have most of it left.
Foundation member #61 of FB/EK Holden club of W.A.
I've shortened two Commodore diffs now one for my FC Sedan and one for my EK Ute they are a good diff, have good rear disc brakes and can get LSD however because they are fairly easy to shorten they are becoming dearer.
. 
, but it works.
. 13inch wheels with 185.R80. . 13inch wheels with 185.R80.
