Help ??? re: Cyl head construction

[MyKarina]

Here I am looking to get myself a T4WD and been scratching my head with wonders , as I recall japan went to no lead a few years before we did , back in the mid 80,s , so this leads to the question of the build or make up of the cyl head components , Someone here I hope will know from experience during the rebuild of the cyl head ........ ? So the question is ?? Does the 85 thru 88 cyl head have hardened valve seats needed for no lead gas ??? are the valve guides iron , or even bronze/brass ???

[arbskynxnex]

These cars are unleaded only, so everything in the engine should be set up for it.

[Lil Beast]

Aluminum head with iron valve guides! As for hardened steel got no clue! I know stronger valve springs are available! I'm sure if you use the search tool on top the page! All you're questions can be answered!

[Petros]

the valve guides and valve seats are cast iron and hold up well, as do the hardened steel valves. If you rebuild a head I would replace all the exhaust valves (they typically suffer heat damage, not worth the risk of reusing). You may have to replace the guides, depending on wear, seats and intake valves can all be resurfaced without any durability issues. You will need new valve stem seals of course as well.

Also you might want to do some changes to the head gasket and combustion chamber as I outline in my "repair guides" thread on "head gasket replacement-petros method".