mk1 burning oil?

[N0V4 JACK16]

i have recently had my cam changed, new lifters and rockers. for some reason everytime i top up oil, the dipstick reads fine and afew days later it reads empty. i'm sure its using the oil but theres no smokey smell from the exhaust, puff of smoke when it starts either. i was told it could be the oil seals but i won't think it would use that much oil. help anyone?

[mowgli]

valve seals, piston rings... is there a leak? the breathers can block up on the early small blocks...

[Will F]

If it was using/burning that much - it would be smoking like a chimney!
You would notice if the seals/rings were fecked for sure...