There seems to be a bit of confusion and myth, so I think it's time to clear the air a bit.
Head gaskets require flat surfaces on both the block and the head to seal properly, the block is heavy enough that it usually won't warp, heads on the other hand will and do warp very easily. The factory allowable tollarance for warp is 0.003 in. (not very much), any thing more than this will require that the head be surfaced to make it flat again. This is no big deal to have done, just a little work to remove the manifolds so it can be done.
When reassembleing it is necessary to torque the head bolts in the proper sequence. This needs to start at the center of the head and work evenly towards the ends. also it needs to be done in steps, as in step 1 torque all 10 bolts in sequence to 25 ft. lbs., step 2 torque all 10 bolts in sequence to 40 ft. lbs., step 3 torque all 10 bolts in sequence to 55 ft. lbs. There are reasons why it needs to be done this way, if one torques the center bolts to full torque and the end bolts are loose, it will warp the head, and by torquing in steps it will allow the gasget to seat/seal better and help to prevent blown gaskets in the future.
You may have noticed that I put the final toruqe figuere at 55 ft. lbs. instead of 49 ft. lbs. like most manuals show, this is because at 55 ft lbs. the seal is better and gaskets won't loose seal unless the engine is sevierly overheated.
As for head bolts, the A series engine uses 2 different ones, the one that goes in the center right (distributor side) is different from the other 9. the oiling system for the valve train (rockerarms) feeds oil through this hole, putting the wrong bolt in that hole will restrict oil flow to the rockerarms and valves. Under high rpm conditions if the oil is restricted to the valve train it will cause excessive wear and possably nonrepairable damage. I have seen some so bad that the rockerarm shaft had grooves worn into it deep enough that the valves couldn't be adjusted.
hope that this helps and good luck.