Hi
I am new to this forum and I am looking for advise on valve seat inserts.I have a 1968 produced slant six cylinder head ( 2843169 ) in which I wish to put over size valves in it.What I wish to know is there enough material in the head to allow machining for hardened valve seats for 1.5 exhaust valves?Also is there enough room for oversized inlet 1.78 valves without interfering with the exhaust seat insert?

My heaqd has hardened seats for 1.72/1.50....dont know about 1.78

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Thanks for the reply Sandy.Its great to be able to get help on the forum before getting into trouble.Do you know how big I can go on the valves with a virgin bore without notching the bores?
Thanks

Old-Vc,
I just finished machining my cylinder head for exactly what you want. It was no problem fitting 1.78, 1.50 valves. I used early Ford 289 non-rail type 1.78 intake valves, and single groove Chevy 1.50 exaust valves. I had hardened seats put in at the same time. I hope to do a write-up with part numbers for everything.

Thanks for the reply valiantboy.That was exactly the info I was after.How big are your bores and did you knotch them for valve clearance?

The bores are undetermined yet, but probably somewhere near 3.5 or .100 overbore. I had the block sonic checked to see if the cylinders were good enough and they were. I also just bought a couple OZ. head gaskets that have bore diameters of 3.66. I think I remember reading .60 overbore is adequate for big valve heads. The DOC. and others would know for sure.