Looking for stainless replacement valves for 340

I saw these, good price but the length is about .050-.075 longer than stock. That seems like a lot. Maybe I'm wrong, lol!
There are more knowledgeable people here that could advise on your best course of action. Iron heads, unknown cam specs, springs etc. If it were me I would look at longer valves, springs to suit, opens doors to a little higher lift cams without possibly having to cut the spring seats, shim the rocker shafts and you're done. I guess:)