Tachometer

Was the block deck checked? It too neads to be smooth and flat.

No, I was told it didnt need it and I did the headgasket in late August early October and havent had any problems untill yesterday, I did notice crud on the piston heads whats that caused by?

"...crud on the piston heads" is likely to be combustion by-products...primarily carbon.

Yes it was resurfaced new valves ect, i torqued in sequence and adjusted the valves perfectly, i dont understand why it would blow again

You didn't answer Jon's question

did you "RE TORQUE" the head after you got it to operating temp after first torque? after reaching operating temp you are supposed to re torque, and re adjust the valves

Valves yes, head no. nobody I asked (at the time) said I had to do that

Valves yes, head no. nobody I asked (at the time) said I had to do that

Most of your modern cars that use a high-tech head gasket do not need a retorque after the head gasket has been replaced. In your case, as in a lot of older engines, the head bolts should probably have been retorqued after the engine has been run and has been warm.

so if i retorque them now i should be ok?

If all you have is a seep, then probably yes, you would be OK. Can not hurt, and all you would end up doing if it continues to leak is take it apart. Do the easiest first, re-torque the head.
My take on it.

do I have to warm it up first or does that matter at this point?

At this point, it should not need to be heated up, the expansion of running has already occurred, Now is the time to re-torque the head bolts.

My opinion, others may vary