Everyone has their own thoughts behind things like this. 2 and 1 half of the other kinda thing. Either way it's not like a vehicle is going to fall apart with or without silicone. I just liked the idea of completely sealing in the hole (dead air space) from the inside of the light mounts to an inch or so around the underside of roof. For all I know it will rust out on me causing a waterfall. I had good luck with my old Truck so I stuck with the same procedure

Rick...

 

6 of 1 and a half dozen of the other?

 

Yeah,,, exactly. What ever floats your boat.

 

Bump for my own future reference AND for a great installation job. I'll being this soon to my 2010 F250. thanks!

 

How certain are you (or anyone reading) that the 5.5", 10", 8", and 20.5" dimensions are correct? I want to nail the layout perfectly. THis is something I can't fix if I screw it up.

 

The only way for you to know for sure is to go find a DRW F350 and measure them.

the 8" and 20.5" marks 5.5" back look right enough.

 

TR,

Best write up on this EVER. Thanks a million for taking the time to help people like me.

I am going to my buddy's house in a few days. He has a 2008 that came stock with the lights. I am going to measure his to be certain on the numbers. And I'll also check to see if his has the "open air" space around the lights. I wonder if this is because Ford has used the same lights for a while? And rooflines changed a bit over the years, but the lights didn't?

Either way, thanks again for the write up. Same with your fog light install.

I'll install my cab lights in a few days (as long as they show up Tuesday like they are supposed to), and fog lights the following week. Going to be using your writeups as references.

 

I will note that my clearance lights have settled over the past (almost) 2 years. The gaps are much less noticeable, and some are gone.

...still no leaks.

 

Nice. I'm trying to talk myself into installing some on my 04.

 

Go for it. It's only 15 holes, measure, measure, measure took me two years to talk myself into it. Use the right tools and do it .

 

for anyone considering the recon kit over the oem I found this solution to their cruddy kit

Mounting Recon cab lights - Ford Powerstroke Diesel Forum

but I suggest oem

 

Just measured my buddy's 2008 truck that came with them from the factory. From the rear edge of the windshield trim to the front edge of the light was 3.5". And from there, the posts measure back right around another 1.5".....maybe 1.625", so the total from windshield trim lip edge to the posts would be around 5" maybe 5 1/8".

The extra .5" is not a big deal, but I thought I'd put these measurements up here. But his lights did sit flush all the way around.

The 8" and 20.5" were right on.

 

And the factory lights all point straight ahead, parallel to each other, correct? Their aim does NOT follow the curvature of the windshield? I just want to double/triple check.

 

Correct, they aim straight, but also form a bow that follows the curve of the windshield. So if you drew a straight line across the top of the roof right behind the windshield, the center light would be closest to that line, and the outside lights would be the farthest from that line, but they all point straight down the road.

Here's a sketch I made using Paint:

 

I just did this install last month and its not hard to do. Just take your time. Make sure you have sharp drill bits. The roof is very soft so you dont want to lean on it any more then you have to. And I definately reccomend the knockout tool. BTW I used OEM lights and they sit flush. Here's the link to my install.

https://www.ford-trucks.com/forums/9...ce-lights.html