Chain housing leak
 

Did my 72 E stock rebuild using Wayne's book. Replaced the original magnesium chain housings and covers with aluminum as suggested. Seems like I have an oil leak at the chain housing/case seal
Engine runs great, thanks Wayne!
But any tips on how to fix the leak?
Is there a way to do it without disturbing the timing, or should I just bite the bullet and start over.
I used the gaskets dry as recommended.
Should I use a sealant?
Should I have the housing surfaces machined?
Any and all advice appreciated.

Loctite 574 on gaskets.