its very easy to do yourself, and the head doesnt need to come off.... i recently replaced mine.... i got the
www.lcengineering.com steel guides because they are a bigger company than doa and have a better reputation. i also got the standard timing chain kit from
www.engnbldr.com in total, i spent about $200 on everything, but i made sure it was built to my specifications. i did all the work by myself and it was pretty easy, i even replaced my oil pan gasket as well..... start to finish of solid working is about a day, and thats how long it took me, but if you are really gungho on it, it shouldnt take that long..... let me link you to a couple of threads on otehr sites about it..... one is yotatech that i started, but i got banned there, so i cant respond there.... and the other is from roger brown, he is a well respected member of the toyota community
http://www.4crawler.com/4x4/CheapTricks/EngineMods/TimingChain.shtmlhttp://yotatech.com/showthread.php?t=51869
