Blend Door- Where to cut HVAC Plenum?

[bphodgesus]

Hi all. Do we have a consensus on where the best place to cut the HVAC Plenum is? Is it better to cut the bottom (side facing the floor) if so what landmarks would you use to make your cuts? Is it the "front" the side facing the passenger compartment? Again what would you use to guide your cut?

I am doing a little rehab work on my 1998 Exp. Limited, I just replaced the radiator and driver's lock set. So far 125k this has been a good dependable car. The only repair needed was a cracked passenger side exhaust manifold.

Thank you.

 

[bphodgesus]

Oh just fyi

I have read all of the blend door posts at least twice, but am not sure of the best, and least likely to cause problems location to cut. Thanks.