Now that I am done peeing on a fire hydrant, I am trying to help, if you don't want to agree, no need to and I am done talking, but from experience I do not think it's good advice for an FE, and I'd politely warn you not to do it on your upcoming build.
If this were a Chevy style rubber gasket, thinner gap and wider footprint, I'll give it to you in a heart beat. Ultra is a bit better than RTV, but not much and the china walls on an FE are different. Too much you push into a return, but you need a lot to fill a gap and the block wall is narrow. What generally happens with a non-adhesive type of gasket maker is that it lasts for a bit, and once oil crawls behind it, it lets go just like RTV.
Personally, I have never had an FE end seal leak. I have had some fight me until I was happy, often machining the intake, and even taping off the valley and using a coarse file to knock down a cork gasket to make it perfect, but pure sealer on an FE IMHO only works if you have an adhesive/gasket maker, and a tight gap.
OK, I yield to the fact that the FE is special. Seems all Fords are special, and no other engine is. It's all I hear on Ford forums...how "special" Fords are that the the laws of physics and chemistry don't apply to them like other engines. I guess the several FE's I've built and/or changed intakes on (admittedly only a handfull) somehow don't count toward any real or relative experience compared to others here but in my ignorance and lack of experience, I'll take a chance and keep doing what has worked really well so far.
Scott, I am not trying to be a pain, but no shit, old heads here have some tricks, and the FE has some unique (call it quirky) stuff, like it or not. China walls are imperfect, rear mains, thrust bearings, valvetrain etc. I just spent the day on a 67 400 HO Poncho, which leaked like a sieve, I went to the Poncho forums to see what guys were doing lately to seal them up. When I was building 389s and 400s, nobody had a one piece pan gasket and nobody had a 1 piece rear main seal. I chose the new style gasket but not the rear main because I didn't like the idea of threading that in with the crank in it under the car. Doesn't mean anyone was wrong (well maybe me if it leaks LOL).
Please do it your way, I am the last guy to poke someone in the eye, but sometimes the guys who do a lot of them aren't stupid or were bit by things. We disagree in here, try to explain it, and I would guess that every so often, we try each others tricks, just like any old wrench puller would when he sees someone else doing it and toss the ideas we don't like
Case in point, in the 90s when the original FE forum was running, NOBODY wanted to run stock style hyd rockers on an FE. In fact, used to be the "limit" was .500 lift. You went adjustables or rollers. Nowadays, after Brent and Blair really led the pack, many of us now see that they work better on a HR cam, lighter and easier and stable as hell. Who would have thunk it? Now it's mainstream HR stuff and smarter than a big set of rollers in many cases.
Second case, in the 90s you couldn't GIVE away a Streetmaster and everyone wanted a Sidewinder or Portosonic, then Jay started testing and fipped it all around
I am looking forward to your engine build, as I do anyone else's in here. You mentioned some different choices in cams from Straub and I see he uses some different combos on Speedtalk, looking forward to it, they tend to be milder intake, wider and more exhaust, looking forward to see what you come up with. You also eluded to some math and CSA thoughts, bring it on, would love to hear.
BTW, I used the last of the tube of Ultra Blue and some Ultra Grey today on that Poncho and my hunch is it'll work awesome
