Pinto Head Identification

Hi guys,
 
I've sourced a pinto from a 1988 Sierra.
 
The block was built in June 1988, I've gatherered that from the stamped numbers on the side of the block. The stamped letters on the one of the gearbox flange lugs confirms that it is a high compression unit out of a Sierra, as does the weber carby with all the electronic stuff hanging off it (electronic choke, etc). It is a carb unit, so no tear drop ports.
 
The last puzzling thing is the stamped letter 'I' on the side of the head (to the top left of spark plug hole no. 4). I really want to ascertain whether this head has hardened valve seats or not.
 
Normally, 2.0 litre heads with unleaded valve seats are stamped with 'P', 'PP', 'R' or 'RR'.
 
I can't find any solid reference to the I stamping signalling unleaded valve seats. Ive tried ringing the parts department of a ford UK dealership but they say only the technical folk at Ford HQ could help me... and id have to call a premium UK line to get through. Not possible from AUS.
 
Any ideas??
 
PS Side question - if it doesnt have hardened seats, do I have to get hardened seats put in to all 8 valve seats, or just the exhaust seats?
 
Cheers
 
Nick
 

Hi SHaun, thanks for the answer.
 
Yeah, I did end up digging a little deeper and found someone who had 4 heads marked with 'I" and he said that they none of them were "unleaded-friendly".
 
I spoke to a local machine shop and they have quoted me $35 per exhaust valve seat. Not too bad at all

Every day I have been driving my 1600 Escort completely stock standard engine with unleaded fuel since unleaded fuel first became available.
The head was first removed in 2009 to replace the head gasket. The head gasket I removed was the original Ford gasket fitted by Ford in July 1979.
The head does not have hardened seats.
I do not use fuel additives.
Absolutely no problems, or any perception of increased wear on the engine.
 
Maybe the need for hardened seats is questionable unless you are racing, or are towing heavy loads.

Thanks for the pointers guys.
 
Yes, this will be my daily. I should fill in some details so it all makes sense.
 
I am yet to buy engine. Have seen it with rocker cover taken off - rest of engine remains assembled. Original inlet manifold with standard Weber DFTH 30/34 is still in place so pretty damn sure this engine has not been toyed with. Absolutely no sludge marks under the rocker cover and cam has no visible wear. It looks promising!
 
Im able to do a compression test before purchase (got a bellhousing and starter motor for the job).
 
Before I sink this puppy in my mk2 I am really keen on installing a high torque cam (Burton BF134 or Kent FR30) and even upping the compression (through felpro gasket alone or with head skimming + felpro - not sure yet). I'm aware that I will have to replace followers and valve springs (and valve stem seals whilst I'm at it. Will have to address valve to piston clearances as well.
 
I've got a mate who should be able to help me with setting up the valve geometery - but prepared to give it to an engine shop to do assembly if it proves too difficult.
 
As the head will be taken off and dismantled anyway, I thought it might be an idea to get the exhaust seat inserts fitted. I think the $35 includes blending - but not totally sure, will have to ask. Skimming the head will set me back $80.
 
Any tips or guidance at this stage? Am I approaching this in the right way, or am I just opening up a big fat can o' worms??? Im just trying to go off what ive gleamed from turbosport, hammill and vizard so far. Im not keen on putting in oversized valves - at most cleaning up the ports with the help of a friend.
 
Will retain the 32/36 weber - bike carbs as a future possibility, but not even on the radar. Pretty dead set on cam spec - suits my street rat needs down to a T