302 head progress and questions

“In theory”, a valve job would have been done(seats ground or machined) to facilitate the use of the bigger valves.

I’ll go against the grain here and say that unless that previous work was done very poorly(very possible), and/or there are noticeable issues with how the valves are sealing, remachining the seats to “race quality” standards........will not have much impact on the cars ET with the type of combo you’re working with(low hp/ci).

But, someone needs to assess how serviceable the condition of the seats and valves currently are before making that call.