Seems I was beaten to asking AMS myself... https://www.evolutionm.net/forums/sh...threadid=36854

 

Yes you can and should clean the threads (hole) out, and it's done rather easily. I did it to our evo and at 26psi (380ft-lbs of torque at the wheels) the headgasket holds just fine. I've also done it to a bunch of DSM's and I don't recall one problem with a head gasket pushing after installing head studs like this. To be honest, I'd make much more money on the job if I had to remove the head to install the head studs, but from experience I don't feel it's necessary and we can do the job quickly and inexpensively with the head on the car. I'm not trying to argue with anybody here, just sharing my experience with what we've done.

Martin

 

Like I said before - IF ams says they can do it - trust them - they know their stuff for sure

On my own personal car I would lift the head - BUT

Certainly replacement with the head on must be better than the streched out ready to burst factory bolts

 

Hey Martin, there are a few specific questions on the subject in your forum (above link)... customer questions.

 

hey Al,

did you change these bolts on your beast of an engine? or have you not found them to be a problem yet...others were saying it wasn't the horsepower that did it but the detonation...whats your take on this?

 

Extreme cylinder pressures will push a headgasket. Detonation creates huge cylinder pressure spikes. Torque is a directly related to cylinder pressure, so the higher the cylinder pressure the higher the torque (to an extent). We had stock head bolts in the car up to the 350whp level (don't remember the exact torque) and 24psi, but this was on race gas and no detonation. Easiest way to check for detonation is to read the plugs.

Martin

 

Yeah - what martin said

IF I was using my evo with over 300 whp I would replace those bolts for sure - its not worth it - the two guys I knew who blew a head gasket also lost their head or engine !

 

i want to ask a question about the whole STUD issue. My confusion here is that from how I'm reading you are basically drilling straight through the block and getting a head bolt that will use the bottom end(with the stud) to anchor it in place? I'm just trying to figure out what exactly is done to put in new head bolts?