hi guys i am a bit confused on something that just happened.I had taken my heads of my 70 383 to a machine shop to get a valve job and generally just checked out.Bear in mind the motor ran great except for a little smoke when you got on it really hard.it didnt use any water a little oil but nothing really bad.Anyway he calls me and says the heads are no good because they have cracks in the exhaust seat/valve area.is that correct being the motor ran fine and used no water.he said that as big as the cracks are it should of had some kind of problem.What gives ...is he trying to hose me or does this happen?thanks for your input.

Not surprised exhaust seat cracks are common. cracks are usually pretty shallow and a long way from any water. Cutting them 1.81 exhaust valves would likely remove them. You should replace all the valves there are stressed from 40 years of heat cycles and the past 20 years of hotter burning lo luberecand fuels.
But with todays fuels you should really have hardened exhaust seats installed also + the valve job and you will need valve guides, and should put in new springs retainers and keepers so this is what you are really looking for.
http://chucker54.stores.yahoo.net/perpalas84ch.html

but will cracked exhaust seats leak anti freeze?that is what the machinest said?

Have the shop pressure test them.

Randy

Cracks are common, sometimes they don't cause problems or leaks. But you never know...


I would invest in a set of Edlebrock heads before I spent any money on rebuilding your old iron heads.

Sorry but what was said, by the time you replace 40 year old valves, new hardened seats, guides, springs, etc, your better off with Eddies.

I bought mine for $1250. a few years ago from Flatlander Racing.

Cool title!

i thought about haveing them pressure test them...but i dont want to keep dumping money in them if they are shot.the thing that stumps me is this.There was no problems what so ever.that is what is so weird.no leaks no running problems what so ever.in fact it was a strong [Edited by Moparts - Family Friendly Site - Keep it clean].Dont know what to think.thanks for your input.and yes it is a cool title....lol

Throwing any more money at crack prone iron head is a bad deal. you could spend $1000 to $1400 on them and have them develop cracks eleswere!!
You will love Eddies and fuel problems go right out the window