Hey guys, 
I have finally started getting into the guts of the car now, however I'm finding that everything is very dependant on one another.
I've got a 2 door mk2 which has forest arches fitted.
At the moment I'm using a bog warner 1.6L. However the intention is to convert this into a rally car. 
I'm thinking that buying a volvo 240 axle end to end.
Volvo calipers for the front and doing a full volvo brakes setup with the diff.
Is this a tricky modification and are the volvo diffs strong enough to take a pinto putting out around 140hp?
( I have seen a few posts on people considering volvo diffs but no one with one finished!) 
Thanks! 

Borg Warner diff and brakes from r31 skyline gets my vote. Same diff as falcon and commodore but I prefer r31 brakes/handbrake setup and are already 3.89 or 3.7:1ratio which is suitable for most escorts. not too heavy and plenty strong enough. Good axles and LSD readily available, and other ratios to choose from.

I got told that the bog warner diffs out of the mk1's were pretty ****house?

 

****house in what regard? it served its purpose well.from my experience mk1 Borgie is actually slightly stronger than a standard mk 2 escort 'English' diff.

Mk1borgie is entirely different to above suggested BW78 (r31,falcon,como.... Diff)

Cheers

In a previous post when I initially got the car a few of the forum members said they were crap and that most people upgraded to the mk2 diffs

The mk1 BW is only cr@p cause its available in (99% of the time) 3.89 , they Prolly can handle wads of powers ...well upto 200 depending on driving antics . As for fitting a lsd I was told a sigma GRS turbo diff can fit but why bother! R31 is a decent choice and cheap. Volvo will work but heavy tho it's a Dana 31 and cogs are endless as are  lsd's like TruTrac($400usa) / air lockers $900 or just weld it solid ! 
Even I'm still thinking what to use in my van ..

The Volvo may be a good idea at first however myself and others that considered this route decided against it because there are no LSD's avilable for it that are the "clutch and plate" type.

If you are going to rally the car then you need to look for a diff with a 4.44 ratio as a minimum.
The 3.89 is ok for a fast road car but not very useful for a rally car. You want the car to be able to accelerate quickly out for corners more so than having a big top end speed. I personally use a hilux diff in my rally car with a 4.9 lsd. Yes these are heavy but have many ratios and lsd options available as well as having near indestructible axles. I use EVO4 front rotors with vs commodore front callipers. This also gives you a vast choice of pads. Hope this helps.
 
Cheers
Craig

Surely the good old English axle can handle 140hp in a dirt car?  Diffs break when power is put through grippy tyres so surely a rally car on a loose surface will not put enough stress into a diff?  Suppose the works cars used an alternate diff (atlas?) though...

English axles don't like the shock loads you get in rallying, HP has very little to do with it. The combination of slip then grip, shock loads from hitting ruts and bumps etc sideways is too much for std English axles and diffs in my experience. I had a BW78 built up (as RS 2000 has suggested) with a 5.1 centre. It's big and heavy, but I'll never break - and after so many DNF's with the English that's great peace of mind!