I realize this will probably come off as some Internet guru who just likes to complain, but I'll let the numbers speak for themselves.

One set of numbers is from a clean, used 452 head with the OE valves and OE valve job, the other is from a 452 head than was done at Aerohead like what the op is getting done...... Big valve install, no porting:

Lift--------A/B
.100---61.4/ 67.8
.200--123.6/118.3
.300--184.8/169.5
.400--205.7/198.4
.450--215.0/207.9
.500--222.5/219.9
.550--226.2/224.9
.600--225.1/224.9

The much better option, especially for these milder applications is to retain the std valve sizes and do some mild bowl porting, which not only increases flow but also has much higher discharge coefficient rates(more flow, smaller valve = higher air speed around the valve).

902(1974 head) head with 3 angle seat(stones), back cut OE valve, and very minor bowl blend:

Lift-------flow
.100---67.2
.200--139.0
.300--202.5
.400--230.5
.450--237.0
.500--240.7
.550--243.8
.600--245.7

The big valve install without some accompanying porting is a step backwards for most applications, IMO.
Even if the flow was the same, or slightly higher, the speed of the air around the valve as it leaves the port and enters the cylinder is slower(same amount of air flowing through a bigger hole), which results in more reversion and less efficient cylinder filling.