No Blue Thunder only recently began doing the C7ZX version. They never did the COBRA lettered version.

I will have to double check but I think it is strictly from the intake valve relief to the back side of the top ring recess. I don't think it really touched the top or bottom of the ring landing. It was not thru to under the dome. These are flat tops. I will take a closer look at the pistons and get back. They are not mine.

I see exactly what you mean by it may not really matter. The gas preassure is already hitting the top of the ring and getting behind the ring itself, which is all that small notch will allow gas to flow also. Any chance of oil some how being sucked up from below the ring on the intake stroke thru that small hole? (unlikely?)

    I GUARANTEE the piston will  fail , it is only a matter of when.  When vertical gas ports are drilled ( .043 hole) into the top of the piston , careful attention is paid to AVOID putting a hole in either of the two valve relief areas to prevent breakage. This is not a guess , this is from 30+ years in the piston industry and experience with the subject.
     Randy

    The typical "crossover" tubes were 4 and 8. This helped the firing rotation to where only two cylinders fired out of sequence in the collector instead of the usual four. Doug did it in an attempt to make the primary length more equal. A "true" 180 firing order set would have 4 tubes crossing over and are NOT worth the aggravation or expense. The tubing diameter and collector sizing make them VERY RPM sensitive. I ran them for about three years before I wised up and put on regular four tubes and picked up.

    No argument on what you found Jay but you might have made more with 58's like Ford did in the day. Now on a 289-302 a Victor Jr and 750HP are usually 30 better than Webers. I've done it more than once.

Although expensive, I think you best bet for a intake, would be a sheet metal Weber 48 IDA or even a a 48 IDF, cheaper and closer spacing.

     Frank  ,
       Webers , in an IR situation are too small to feed a 302. The best manifold I tested was the single plane , dual four using two 720 cfm carbs made specifically for the tunnel port 302. There  were some more exotic "bathtub" dual four intakes but the giant plenum really lost bottom end torque. A friend has one of these that backfired and "expanded" the top cover. Luckily it didn't explode!
      BTW , Scott (pbf777) has one of the ultra rare 3-2bbl tunnelport  manifolds. Few know it exists and "I" only know of the one Scott has. I owned one of the single four TP intakes but it had fuel distribution issues because of carburetor placement. Ford was really desperate to make the engine work and it didn't.
    Randy

    Gentlemen,
        I am one of the few that have used the "street" head which has some significant differences from the race head. I also ran the race head in '69 when they were "given away" literally . The first is the smaller valves Brent noted and because of the guide spacing it is not possible to install the race valve which was 2.150 in final form , though they did do some at 2.11 according to my SK notes. The tunnel port head had over thirty  revisions during the '68 season on the "race" heads. The street heads had a poor exhaust port (compared to the race head) as it was made for smog tubes. My heads were plugged and ported but the flow was about that of a C6FE head. BTW I had one of the best pairs of C6FE heads and the intake flow was a stout 260.
     My engine was a 331 so an additional 40 inches like Brent is using will completely change things for the better. It would be over 540 HP from my experience without taking Brent's skill and ingenuity. Mine was about 480-490. The intake manifold is one area where big gains could be found. There was/is a rare single plane dual four that made an honest 20-25 MORE than the more common dual plane. The only other possibility is a "small port" dual plane dual four that was made or the ultra rare single four ( two known to exist).
   I am anxious to see how Brent does on this one.
  Randy

   Jason ,
       I haven't done the Galaxie , but I own two GVs and see no reason why they would not fit. The unit is narrow enough to stay in the tunnel and doesn't stick up above the adaptor , height wise. Mine are both in Ford trucks but I could give you dimensions so you could verify you have room.
   Randy