well im definately going irs. Only thing is. looking at the drawings, is the bit that the diff mounts to flat to the floor of the actual car?? because the drawings dont seem to say from what i can see?? and to me it should be. any info is great. thanks. john.

Hi John, what Diff are you using?

Diff is mounted so that driveshaft outlets are slightly higher than centre of wheels when under load. (Well, mine is!)

This then, to a certain extent, determines axle centre line and height.

If you are using Sierra diff, then you need to weld (predrilled) plates to chassis tubes that are rearmost of transmission tunnel, facing boot.

I may have pics in archive.

HTH

ATB

Simon

[Edited on 7/3/09 by Simon]

Here's mine before the diff is dropped in.

Wedged the diff where I wanted it on blocks of wood etc, then bit of card to make a template for the mounting brackets.

Transfered these to a bit of 1/4" plate, cut out and bolted on to the diff and welded in place.

The diff nose sits 1/4" above the lower chassis rail on mine, as its home brew I added a bracket at the back, most people do not other with this but I suspect the better gusset the front brackets.

Regards Mark
Rescued attachment OSR Chassis 18 Nov 2005.JPG

im using a sierra xr4i rear diff.

See MArks pic then - that's how similar to how mine is - maybe a pic in archive.

I drew my chassis (sideview), diff, and wheelss fullsize on the building board once chassis had been fully welded.

ATB

Simon