If you figure in the valve lash for that cam, you're back down to around .500" or so anyway. I have used an MP 292/509 with Edelbrock heads and their stock springs with no problems whatsoever.

1969 Nova
454/M21/3.31
Mild mid-11 second weekend cruiser

1994 F150 XLT Super Cab 2WD
5.0/4R70W/3.55
(Daily driver)