I don't know if this will bump up to the top, but I have a follow up of a sorts on my BBM heads.  I started working on them with the 2.080/1.600 valves, and I could not get over 312/200cfm no matter what I did to the ports.  The exhaust simply would not pick up flow, only 210 with a pipe.  That frustrated me to say the least, so I ordered another set of heads, and they came yesterday.  The seats and ports are completely different from my first set of heads.  The seats are flush with the combustion chambers, and there are no voids under the seats where the seat is standing proud in the ports.  SOOO...hopefully these should flow differently than my first set.  It always amazes me when I hear of flow numbers that I cannot come close to duplicating on my flow bench.  I have been at this for over 40 years, and when I cannot equal someone else's flow numbers, I start looking for the problem in my work.  It is not my work, it is these first set of heads are just different from the second set.  I feel confident I can figure out the exhaust ports' shortcoming on the first set.  We shall see.  Joe-JDC

It only flows 230ish cfm through each runner unless you deburr the welds inside the runners and open up the throttle body flange.  The heads only flow 180ish cfm.  Sorry, it is not lightning fast, only marginally faster than any 5.8 of the era.  I had a 92 with 5.8 I bought new and drove for 14 years, so I have BTDT with ported heads, ported intake, ported plenum, and the GT-40 upper plenum is a bottleneck, period.  I still have one.  A healthy 302 runs out of steam with the GT-40 around 5200rpm, so to say the 351 runs great, is not honest, IMO.  I built one of the first 351 EFI conversions back in 1987/88 in my 86GT, and even ported the GT-40 throttle body flange to 75mm, etc.  It was great but still went flat in upper rpms because of lack of airflow.  A ported Cobra plenum that has been cut apart and welded back together can flow 300 cfm, and a ported Explorer plenum cut and ported can flow 300-305cfm.  I have done more of that than probably anyone in the USA, and had several in magazines back in the Super Ford days.   Joe-JDC

I have been watching this with interest, and think it is a good representation of what can be accomplished with the right parts selection.  Good information, and thanks for sharing.  It would be interesting to compare these engines with a Victor that was just gasket matched.  Joe-JDC

Having been a life-long Ford owner, my last two trucks have been Tundras, and I am hooked.  I recently towed one of my mustangs to Florida from Texas, and averaged 14.0 mpg, and empty 19.7 mpg.  On another trip to NM, Colorado, I was averaging 20-22.2 mpg driving between 68-72mph.  This is with a '14 Tundra Crew Max Platinum.  The supercharger is an option that is usually dealer installed and tuned.  I am happy with my Tundra the way it is, but I can see where a single cab would be really quick.   It is supposed to turn a 13.7 et without the supercharger.  Joe-JDC.

Not sure on the '55, but the '56 and '57 seem to have a little different suspension and frame.  I know I have seen a SOHC in a picture but not sure if it was a '55 or '56.  I have ridden in a '57 with 427 and toploader, and it was VERY quick.  Joe-JDC

Boss 302 cars were high performance cars with special engines.  The Boss 302 head is slightly different from Cleveland heads in that it has provisions for water to go through the intake manifold like a regular sbf engine, but requires special head gaskets, intake gaskets, intake manifolds, etc.  They are low production cars, and engine parts are relatively hard to find for restoration projects.  I have a NOS Boss block that I have owned for over 42 years just waiting on a car to put it in.  I have a NOS intake manifold that is hard to find, etc.  Boss heads are not just cleveland parts.    The '69 Boss 302 heads had 2.230" intake valve, and the '70 was reduced to 2.190" intake valve.  Joe-JDC

I am not against a cammer!  I have driven FE's since 1964, and have a 1970 Shelby GT-500 I bought new.  I could build one, but I would only attempt it if I was certain I could procure ALL those little nitpicking pieces that drive you nuts when trying to finish the project.  I am seriously considering putting a FE in one of my Fox mustangs simply because they have the room under the hood.  I have an all aluminum 427Clevor ready, but I am like most folks here, I like things a little different at times to surprise folks when the hood comes open.  I just bought a '55T-bird with 3speed/OD.  That is starting to look very tempting for a test bed for several different engines including a stroker Y-block.   Joe-JDC