I am about to start reassembling a 2003 5.4 2v that had a broken valve spring on the intake valve of cylinder number eight. This may be a stupid question, but since I only pulled off the drivers side head, do I have to retime the two cam shafts together, or can I just time the head I removed since the other wasn't messed with?

 

no on timing the other bank that the timing chain was not removed from but everything must be in time if you did not move the other camshaft or crank or replace timing chain then as long as both cams are in time with the crank you should be good. just be sure to double check.

 

All of the timing parts should be replaced.