I currently have an open wheeler disc brake rear end. I want to change over to a VL turbo LSD rear end (ie axles, brakes the lot.) Will this rear end bolt straight up to a atmo (open wheeler) drive train? Or will I need the gear box and tail shaft too? I have heard that the drive shaft is larger is this true?

From what i've been told, the tail shafts between the atmo and turbo auto's are exactly the same.

So how many splines are in my diff? mines already disc rear (from the factory). Supposedly the atmo open wheelers had 25 splines but the majoriy of them have drums ends and they have different axels? So would holden make a whole new diff for atmo calais? Also if the axels and diff is 25 splines can I just replace the center and axels into my housing with a 28 spline lsd ones?

From personal experience i can tell you the n/a discs use 25 spline axles and the turbo / v8 use 28, The n/a drum axles will fit straight into a n/a disk diff with the disc wheel bearings installed. The diff will bolt straight up, the differences in the tailshaft are in the yokes so you dont need to worry about that.

yes but will 28 spline diff and axels bolt onto the orignal housing or do I need a whole turbo rear end?

Yes it will if you change the centre 28 splines will fit.

Anyone know what I should pay for the axles? also how much is a center worth with 3.45:1 gears?