Here are the correct methods for torquing down your head bolts after replacing a head gasket or doing any head work. Also note these procedures are for stock head studs.
Here is a typical #'d layout of the headgasket. It is always a good idea to tighten the bolts in order from 1-10 for each step


420a
1. Torque all center bolts to 25 ft-lbs, torque the 4 corner bolts to 25 ft-lbs
2. Torque all center bolts to 50 ft-lbs, torque the 4 corner bolts to 50 ft-lbs
3. Re-Torque all center bolts to 50 ft-lbs, re-torque the 4 corner bolts to 50 ft-lbs
4. Tighten all bolts in the sequence from #1-#10 an additional 1/4 turn.

7-Bolt 4G63
1. Torque all bolt to 58 ft-lbs in order
2. Loosen all bolts completely to 0 ft-lbs
3. Torque all bolts to 15 ft-lbs in order
4. Tighten all bolt 1/4 turn in order
5. Tighten all bolts an additional 1/4 turn in order.

ARP Head Studs
1. Tighten all bolts to 40 ft-lbs
2. Tighten in steps of 10 ft-lbs increments until the specified torque that you are looking for is reached. This can vary with the amount of boost you plan on running.

 

aparently this needs to be a sticky. . . or we could just scan the page out of the book for the people.

 

What is the sequence for a 2500 Turbo diesel Colt's head and specs

 

I'm helping a buddy with his car and not sure which head he has. It is the SOHC head that came in the 2004 Lancer Rally edition. I've looked up the two head models listed and those seem to bring up a lot of DOHC heads. Which tightening sequence should I follow? Normally I work on mid 80's Dodge motors and we use the same sequence for all 2.2 and 2.5 motors, so I want to make sure I follow the proper method.

Thanks in advance!