valve guide question

[GJCAT427]

In building this new tunnel port project, I`m wanting opinions on using bronze guides in this thing. This is going to be a .600 lift OEM cam and matched valve springs. I used bronze in my 400 shop truck motor many yrs ago with out incident and wondered how you guys address the top end.  Usage is street and strip   

[Falcon67]

If you run aftermarket stainless, you have to use phosphor-bronze as far as I know.  I have only run stock cast iron guides with stock composition valves.  Anything else get's new bronze stuff with Viton seals. 

[blykins]

You can run new valves with any guide.  Cast iron guides and stainless valves need chromed stems.

However, it will be a benefit to you to switch to a bronze guide for a couple different reasons....

1.  The new guides will be already sized correctly for a modern valve seal.
2.  You can have your machinist cut the step off the heads so that you can use a modern valve spring locator that will locate off the valve guide boss.
3.  You can switch to an 11/32" valve stem at the same time.

If the factory guides are worn, you're either gonna need liners or replace the guides. 

If they're not worn, then I would at least have the guides and spring seats cut so you can run a nice Viton valve seal and a positive spring locator/cup.