Safe Valve Pocket Depth

Hey all. Getting ready to put my 383 together for the ‘68 dart. Nothing fancy, we all have a budget, right? The build is a fresh short block, .030 over with Speed Pro L2315 flat tops .014 in the hole. Cam is the Lunati Bracket Master II with [email protected] and .480 lift with 2 degrees advance (over the 2 ground in) Stealth Heads, Lunati springs, Comp 1.5 rockers, Edelbrock RPM and TTIs in front a 2500 stall and 3.55s. I have cometic .027s to keep the static compression around 9.9:1. Dynamic should be around 8.9 to 1. Holley sniper on top.

My question is, (hopefully PRH will chime in) I have access to the Lindy pocket cutter and a junk set of 906s. I was thinking about adding valve reliefs before I put everything together and put it in the car in case I ever want to go with 1.6s for more lift. What is a “safe” depth to cut? I was thinking .040 but I don’t want to risk burning through.

I know someone is going to say take them out and to a machine shop, but I think I can tackle this, and have to save for a wedding in October (but she wants the car there!)