Chris: Mike (offthefront) has been having the engine problems. I don't have any that I'm aware of. I was just curious why there was never a reversion problem with little drop in the rubber exhaust hose. Mine drops maybe an inch and a half maybe two inches total. Russ

Russ,

Sorry for the confusion ... trying to squeeze posts in at work ("continue CPR ... I'll be back in a minute - gotta go post on OSO!" ).

I never had problems with reversion with my stock 454 mags or factory exhaust. I had problems after modifying the motors and changing to CMI exhaust. The higher CMI with 3" rise would not clear the fiberglass lip in the back and the standard rise caused the tails to be almost straight without any downward angle.

I think the factory setup was adequate enough to prevent reversion with stock cams. One has to be careful with modifications ... one change usually means two or three other things need to be changed later to fix the problems resulting from the first! I know your wife understands this ... right?!

I wasn't very clear on that was I.
Yes the wedge was simply to drive the heated inner pipe out to the wall of the outer pipe. I was looking for a cone to drive into the pipe and then drill the water exit holes. That is vertually what Gil does. I couldn't find the right size cone to use so I just made a wedge out of 3/8" plate. Heated 2 areas opposing eachother about 1" long and drove in the wedge. Pulled it out and did this again I think 3 times. This kept the inner pipe nicely centered. Factory pipes use 3 holes 7/16" diamater for water exits. I would guess my water exits were about equal to that.

Payton ...got it ..did you weld the inner to outer ? I worry about my pipes being so long that if the inner isnt "tacked" to the outer that it would eventually cause a crack or break somewhere inside the pipe from Vibration ...If you look at the pic these pipe have the water jacket all the way to the end and then the inner pipe flares out to the outer pipe and its welded solid ....and then there is a 3/4" nipple that runs 90 degrees out off the water jacket and flush with end of the pipe ..there is also a small V at the bottom on the inside which I bet causes a spay of water up into exhaust stream for cooling ....

No, I didn't weld the inner to the outer, maybe you should. The small hole in the bottom is to let cooling water circle the pipe and have a little exit on the bottom so there won't be any hot spots on the pipes.
If you look on my pic, the forward engine with the taller risers, didn't have to be changed, they were already wet pipes. The inside wasn't welded, just pressed out to the outer pipe and the 3, 7/16 holes drilled. spaced evenly around the pipe.

Hows this ?