Flawed data table, disgraced machinists (bullshiters and hacks) additions were let in. The tables are to wide and varied.
A stock head w/1.88 will pick up flow with a larger valve and no other work added or done. It’s been shown and proven for deacades.
To the OP;
However, FWIW, I wouldn’t do the swap unless the next set of heads were 2.02/1.60 & bowl ported and relieved in the pushrod pinch area (made wider) with headers. Your leaving a hell of a lot of power on the table!
