HP is irrelevent for the differential. What matters is the torque:

Engine Torque x gearbox multiplication

A 400HP engine with 275 lb ft torque could get by with a much smaller diff than a blown 400HP engine with 500 lb ft torque.

im in the same boat wondering hich diff is going 2 hold up 400hp im going 2 go 9'' or little smaller!

Yeah... Well I'm looking mainly for options on LSD diffs (doesn't need to be overly strong, just reasonable) that don't need to be shortened. Once you go into shortened diffs the cost seems to escalade a fair bit and then you can use just about any LSD diff on the market...

i heard somewhere (probably here)

the 8.7" diff is like 95% of the strength of the 9" but is like 25% lighter or something

food for though....

there was a perth guy featured in hot4s about a year or more ago and he used a vp commy diff shortend for his ca18det conversion just go for that

I reckon it would have to be a 1960's falcon to be narrow enough to fit a 1200.

Wayland's 1200 needs something heavy duty. He damaged one 9" ford diff. I don't know if he used slicks, but when I saw him race it was on street-legal racing tires. The car has "slapper-bar" style traction aid, but that's about it. That motor has ... 500 lb ft of torque.

But yeah, Chris makes a good point. There probably isn't another 14 sec 1200 with this much torque.

My CA18 used to spin the wheels at the lights on a wet day, sometimes I really can't help it...even letting the clutch out "grandma style". 1200s are so light, that I doubt that the steel in the diff is going to "let go" before the tire/road traction will break. You only need a strong diff if you plan to drag race with ultra sticky slicks. Any 1200 that's not doing sub 10 second 1/4 passes...doesn't need a nine inch.
I saw the axle thickness of the V8 version VN Commodore with LSD diff axles the other day..I've seen bridges held up with less steel...

Chris.

Hmm, not sure but I'm guessing that'd be most likely as the Falcon utes are pretty big. Does anyone know what year, or if they are marked as LSD or anything?

Also, how long is the stock 1200 diff? From the tech section it says it's 3" shorter than the KE30 Corolla diff... but how long is that? :p

could it be a trady ute like a cargo or courier, whatever they are called

In the tech section, it says this:

Quote:

Does anyone have any idea which Falcon ute it is? And I would assume this is not the 9" diff? It'll have to be a fairly small ute to have a diff that will go straight into a 1200 without shortening, how long is it?

Thanks