[RogerFord]

I can't imagine that this topic hasn't been covered extensively, but I'm new around here, so...
I have to change the cylinder head gaskets on my 365 GT 2+2. Is it necessary to change the phosphor-bronze valve seats in order to avoid regression when using unleaded petrol (gasoline)? Leaded fuel will soon become unavailable in Europe, and if it has to be done, then now's the time to do it. Most experts to whom I've spoken say 'No', but I'd really like to get as many sound opinions as possible.

 

['75 308 GT4 (Peter)]

Bronze valve seats can survive unleaded fuel if they haven't been touched (ie: no cutting/lapping). This is due to decades of running leaded fuel will leave trace amounts of the lead to protect the seat.

But this is a gamble and if the heads are off, not worth taking...

Cast-iron valve seats are the required and safe type to run unleaded and shouldn't be too difficult to install in the 365 heads.

If the valves are the same size as the ones used in other/DOHC 365 V-12's and 308's, it may be possible to use their seats... (INT-42mm EXH-36.6mm, Ferrari part #'s: INT seat-105722, EXH seat-102859).

Whatever you do, DO NOT USE FERRARI'S SODIUM-FILLED EXHAUST VALVES. They are an accident waiting to happen...