If you do it. Put it outside. It all drain the pipe for when it sits in between using it. And it won't freeze up if you get a unexpected freeze

I have the same headers. Your problem is probably the joint between the header and the inner extension pipe.
I use high temperature silicone ( red ) AFTER I make sure both pipes mating surfaces are clean and no old sealant.
Mine don't leak and O2 sensor is doing fine.
BUT I do have water dumps that spray onto the top and sides of the upper drive. ( no chalking there also )

I can see the water spray getting turned 180 degrees and sucked back up the pipe.
I have high temp silicon at the slip joint.

Can you post a pic of how you did your dumps tinkerer?

I just installed dry headers on a fresh HP500 had the same issue with water reverting , thank god we caught it right away , we closed the end of pipe with silicone and also piped the discharge bungs with a 45 degree stainless pipe pointed up to my swim platform this way we wash it down and avoid any melting fiberglass

Ok fellas, I've bought some bungs, fittings and discharge dumps.
We're going to TIG them in this week.
Question / assumption:

im assuming I want the discharge bung as close as possible to the silicon rubber ring at the transom.
It would fit and plumb easier in this first picture, but I could get it back another 2 inches of I grind a little notch on the inside of the boat at the top
of the transom and hold the bung right up against the inner transom.

Check out these pics. Again, first pic=easier install
Second pic=closer to the end of the tailpipe by 2 inches

thanks guys

I lost an AF bung too. Matter of fact, I lost 2. My cam is very similar to the 525 cam with a little bit more lift. On some headers there is a little ramp looking thing that acts like a dam. I think most of that moisture burns off before it reaches the actual exhaust port.


At what point is moisture considered reversion?

i just dropped and broke my camera, so no pics.
i'll try to explain where the holes are best i can.
so these are gil dry trs pipes.
the tail is 31 7/8 inch to the weld on the riser
the center of 3/4 i.d water dump is 13 3/8 from tip.
inside the pipe on top are two 1/8 holes 1 inch in from the tip
outside the pipe on the bottom is one 3/16 hole 1 1/2 inches from tip. (drain hole)
the trs is 10 3/8 longer than bravo so if you subtracted 5 3/16 from each end (tip and weld) the water dump would be in same place
from the scuff marks where the tail goes thru the transom to center of the 3/4 i.d. dump is 7 1/2 inches.

been 5 days, so your probably welded hoses rigged and in the water already.
by the way that was a nice write up that mag did on your boat, well deserved

Thanks OOS.

We are welding them them as i type this.
Those measurements are just about what I'm going to end up with as well.

PS. The seat bottoms are 22" from the floor surface in the pantera.