Im guessing no were near it. just compare the size of the boxes,the sierra 5speed is a borg warner 4 speed used with the 2ltr pinto engine + the extension housing(5th gear).
Tha falcons torque would distroy it in a few launches anyhow.(blown a few up behind a 2 ltr)
The falcon xf 4-5speed are cheap as from a wrecker save your self doing the job twice.

 

If that's the case, how come there are hundreds of holden v8's getting around with celica 5 speeds?
The Sierra won Bathurst with monster bhp, so i would have thought that it would be a better choice behind a sluggish stock standard 4.1.

 

The sierra trans are very strong, stronger than the celica or supra 5 speeds. The only prob with them are they are expensive. If you have one, all the better. Would be much stronger than the 4sp from the XF. As mentioned the gearboxes used in the bathurst sierra's were std items, only the clutch was different, and they ran about 550 - 600 hp from memory, and heaps of torque.

Problem is, it will not bolt up to the 250. Give castlemane rod shop a call, they probably have a bellhousing there that would do the job.

Good luck.

 

sierra g/box

which sierra box do you have? there are at least 3, and mabye more different types fitted to the sierra range.

 

The Sierra boxs used at Bathurst were nothing like the road car version. The N/A sierra box (type 9) which is commonly used behind pintos is simply an escort 4 speed with a 5th gear in an extension housing. Anything greater a hot pinto will tear it apart. If this is what you are proposing for your 4.1, forget it, it wont fit or last. The Cosworth road cars had a version of the T5 from the Mustang at the time, very hard to get now, but again would be shagged by the torque of the race cars. The race cars used Getrags (race version, not BMW/Comm style road version) until they were allowed the 6 speed hollinger boxs.

 

If that's the case, how come there are hundreds of holden v8's getting around with celica 5 speeds?
The Sierra won Bathurst with monster bhp, so i would have thought that it would be a better choice behind a sluggish stock standard 4.1.

I relise there are 2 types possibly 3 types of boxes used in a sierra, The box you have behind your 2ltr is a type 9 5speed unless of course you spent 3 grand on the cosworthed engine sierra box(t5) (which I doubt) as you would of had to cut the tunnel out and modified just about everthing to make it fit in the cortina.

Celica 5 speeds are a different story again,as there are a bout 10 different types of them as well.