modified defrost duct and a question

[RICH MUISE]

the pics show what is now the right side of my defrost duct which I modified after tarheel's suggestion. The original duct had a section removed from the center (where the original duct connection was made) to make room for access to my wiper motor, which is now from uder the dash. Also I changed the intake to a 2" pipe to match up with the Vintage Air Gen iv unit I'll be using.
I am wondering about the rectangular recessed areas with a 3/8 hole thru them (see arrows in one pic). As near as I can tell, they have no use. I'm guessing the original design may have been to use them for mounting but was changed somewhere along the line... unless some of you guys have a different mounting, mine only was atteched to the dash using the studs that next to the defrost vents. Maybe another factory vs. dealer installed thing? my original heating system was the dealer installed option.

[suede57ford]

Looks good Rich! Thanks for posting.

I'll have to save those pictures for when I add air to my Ranch Wagon.

Which AC unit did you choose?

[RICH MUISE]

I really wanted to go vintage air..the big gen iv model...it's got the air blend setup like on late model cars. It's a bigger unit, but the shape is designed for 50's and 60's cars with the big tranny tunnels. I got the mock-up unit so I could set up the mounting brackets and make sure it fit before I bought the actual unit. The mock-up unit is returnable for credit against the purchase price of the full product, so it's a good deal. In my modified dash, I don't have a radio or glovebox so I've got more room to work with than most.Also my dash comes down lower than stock, so it'll hide more of the air unit. The gen iv requires two 2" dia inlets ( I used exhaust pipe...also Tarheel's sugestion)for the defrost. As I mentioned,the reason I split it in two was that my wiper motor access is now under the dash, right in the center, exactly between the 2 fresh air vents, so the original inlet for the defrost plenum was right in the way. I am currently working on cutting off the 2 oval rings where the fresh air ducts mounted to the cowl, and will weld the openings shut.
I found an outdoor electric box (for hot tub) with a weatherproof door just the right size for the wiper motor door. I'll cut the bottom of the box off and then shape and mold it to the cowl, giving me an access door that hopefully won't leak....at least less than the fresh air ducts did. I'll post some pics of that when it's done.

[RICH MUISE]

It's in and everything fits, and I've got my fresh air ducts closed off. I'll spend this weekend finishing it off so it looks purdy.  Rich

oops...should have spent more time in  the planning stages...I put the left new duct inlet right where the dash support brace is...now I have to move the brace over. My radio will be in the console, not the dash, so I can move the brace over where it would normally hit the radio.  Damn.

[RICH MUISE]

Pat...or anyone else planning a defrost plenum modification...pay more attention to where you're putting the 2" inlets than I did. I actually ended up with both sides in the wrong place. The drivers side needs to clear the dash brace, I had put it further to the right, trying to give me more room for all the stuff in the dash cluster area,and it ended up hitting the brace, which I had forgotten about. I guess in my case I'd still put it there 'cause my radio will be in the console, not the dash, so I was able to move the brace easily, but that's not the case for most of you guys, particularly if your dash isn't out of the car.
Where I put the passenger side one is giving me less room to work with to install the Gen iv mock up unit...which I am working on now. I got some of the braces made last night and the unit attached...tonight I'll throw the dash back in to see if everything clears. If it does I'll finish up the remainder of the braces and move on to the next project.
If I were to do it again, I'd look at installing the inlets facing down intead of towards the passenger compartment.   Rich

[RICH MUISE]

got the dash put back in temporarily with the gen iv vintage air mock up unit in place and everything fits. I had to notch the dash support brace that mounts to the side kick panel to move the unit over far enough to let my wiper motor door open without hiting the condenser case. I'll have to notch the lower front lip of the dash to make room for one of the defroster outlets.
For anyone with a non-modified dash, the gen iv would probably be tight,and it definetly eliminates your glovebox. I made cuts to my dash, and will be making more, that couldn't be done on stock dashboards because it was the easiest route for me to take. with some extra fidling most of those cuts could have been eliminated. If you are going to do the install, I'd get the mock up unit before adding the new defrost inlets to the plenum.