Vacuum Advance - blocked?

Okay, I've been getting the EFI setup in my 101 and noticed that the dizzy was not advancing under vacuum so I dug a bit deeper and found that the little off take next the the throttle butterfly valve is.......not drilled through?

Why?

Can I drill it out? The v8 misses under light throttle......

Why is it blocked off?

Help!

Jock

is it defenitely blanked or just a small drilling,persum you,ve tried sticking the vacume pipe to your lip when running. im no wiz but i think efi,s have vacume pipies allover, it could be plug in the wrong one. better to take off to drill else you get swarf in engine