Using intake valve for exhaust.

Goodday,

At the moment we've got an old pre-war engine at the shop that needs a couple of new valves. This engine uses the same size intake and exhaust valve. A direct fit is the intake valve for a big block chevy.

Now are there some different kind of quality valves available. I did see that melling has an higher quality intake valve made of "High alloy steel". The same material is named at some exhaust valves.

If i adjust the valve guide clearance, Would it be possible to use the bbc intake valve into our pre-war project?

I would expect it to work perfectly well. Modern materials and manufacturing techniques are much better and pre-war engines were also much less stressed than modern engines. For the small additional cost, I'd replace all the valves.

One thing to be aware of is possible valve seat wear/recession if it's a cast iron head - it may be a good idea to fit a hardened insert if not already done, or use a valve seat lubricant additive in the fuel.