i have fitted the arp nut and stud kit i brought but the rear 2 studs tighten down a lot more that the others should i keep them all at the same length or tighten them down,

 

Set them all down so the SHOULDER of the arp stud is what is stopping it going in any further, if they become bottomed out then when torqued can pull the threads in the block, so check this, I needed to trim 2mm from 2 of mine, but it is totally normal for the rear studs to sit lower, about 5mm if I remember right, doesn't cause any problems.
I use a group a Yb 0611 HG, and torque to 120lbft, leave a minimum of 4 hours then retorque again at 120lbft, failure to let it "rest" for 4 hours before retorque can result in a blown gasket.
tabetha

 

ok the shoulders are sitting up at the moment by about 2mm so will remove this much but got to do all of them all by the rear 2. i have a mountune multi layer gasket going on it

 

Would be odd for all to be like this, easy way to see if it defo not contacting shoulders is to put a bit of paint there, or tip ex even better as quick drying, if shoulder is sitting as far as it goes it will mark the tippex.
tabetha

 

i can still see the end of the thread only one thread but once the gasket is on its well below the gasket face. i would only say 1mm of thread really but the end two if they are screwed in the shoulder is below the deck height of the block i have cleaned the threads with a m12 x 1.75 tap, was thinking maybe i need to use a blind hole tap, the bolts bottom out in the block on all studs other than the end 2

 

Intresting on the 4 hr rest period ..

 

They absolutely must butt up on the shoulder and not due to bottoming out in the hole.
The 4hr rest period I use as the gasket gets looser than it was to start with, ie the gasket compresses to a degree, just what I've always done without problem, that's what I've always done on any car with fibrous gaskets.
tabetha