If converting a glowplug engine to use spark ignition, including installing the necessary hardware to time the spark correctly across a wide range of RPMs, is no big deal, then I need to see what your workshop looks like. That's way beyond anything I could manage with my tools.

CDI systems have been around for decades. Google CH ignition, or RCEXL. No need to overanalyze it, they work great. Yes, up to and over 30,000 rpm. I have 3 sets from when I was running Go's .28 gasser engine.

Here's a real old video of that. In this video I was testing pump E85 with the spark ignition. Ran great so I beat the crap out of it for the camera.

+ YouTube Video

Did some .91 testing on a prop. It idles at 2400-ish. I found that in order to keep the engine from stalling when jabbing the throttle, the low end has to be overly rich. The high speed was messed with some as well. Factory setting is 2.5 out on high, and the throttle jab stalling occurs no matter where it is set. I tried from 2 turns out to 3 turns out. I have not peaked the HSN yet, I need a proper tachometer for that. (I DO NOT want to get hit if the engine detonates and tosses the prop)
The stall thing might go away when in a truck. A prop presents an entirely different load to the engine.
One more thing to try which I'm just now thinking about.. I should pick up the tank more level with the carb.

+ YouTube Video

Raising the tank fixed that. Cool.

Correct, you won't see correct fueling unless the centerline of the tank is level with the high speed needle.

Yeah, I knew better, but was in a rush... hence the terrible test stand I put together. It slipped my mind until I watched the video after the fact.
It runs sweet on the prop. Doesn't even have a rich mid range burble. Getting some actual peak rpm data soon once I get my hands on a proper tach. The HSN is still very rich, but man that engine moves some serious air even as is. It's gonna rip in the truck.

My experience is that correct fueling requires the TOP of the tank to be level with the fuel inlet. If any part of the tank is higher than the fuel inlet, then fuel will siphon into the engine under force of gravity until the fuel level drops below the fuel inlet, instead of the fuel being solely fed by exhaust pressure. That makes it impossible to tune the engine to run properly -- it runs way too rich when the tank is full and therefore can't warm up to proper operating temperature, and compensating for that by leaning the fuel mixture causes the engine to run dangerously lean when the tank is nearly empty. The T-Maxx is notorious for this. I fixed all of my tuning problems with my T-Maxx in a single step by installing a vertically shorter fuel tank; even though the replacement tank is smaller, the truck still gets more runtime because it isn't barfing raw fuel out the exhaust for the first third of the run -- and of course it's much more satisfying to drive, too.

Granted, with a 4-stroke it's a lot easier to keep fuel from siphoning into the fuel inlet since the carburetor is mounted much higher-up on the engine. I suppose it might be necessary to raise the fuel tank slightly to avoid an anti-siphoning effect, but I didn't have that problem on my 4-stroke Revo.

I still need to make up my mind which truck to put my FS-40S-CX into next -- and what to do with the Revo.

Years ago while searching for a solution to the half tank leaning problem, I discovered the "uniflow mod" for HPI Savages half-tank leaning problem. It's basically a clever way to set up the muffler pressure into the tank. It works 100%, the engine runs the same from full tank to empty, and back to full again. It works on Tmaxxes, which as you stated are also known for the problem.

Anywho, my .91 carb is in the stock location, very low. Almost too low to add a filter, but it does fit.
I don't forsee any tuning issues with it, though.

My vote is that you should put the 40 into something lighter than the Revo. Maybe a 1/10 buggy!

Thinking about putting it into one of my HPI Bullets, but I'm currently house-hunting so I have no time for anything. The housing market where I live never calms-down; houses sell within a week, sometimes within a day. Nothing like needing to impulse-buy something that costs a third of a million dollars to keep you up at night. But that's off-topic.

You still have a Bullet, right? Just tonight I did something to one of my Bullets that might be of use to you: Build Complete: HPI Bullet MT Nitro

Btw, what is the "uniflow mod"? I've never heard of it before, but I've also never had any problems with any of my other my nitro RCs leaning-out badly enough to make me care about improving the fuel feed. Anyway, no exhaust-pressure mod will be able to overcome the simple effect of a gravity-siphon from a raised tank downwards into the fuel inlet.

I still have my original drive cups, the drive shafts have worn a groove nearly halfway around the inside of them. I have spares in case it becomes a problem one day. Good idea though on the mod!
Anywho, uniflow is taking the muffler pressure inlet, and extending it down into the fuel, to the bottom of the tank. This causes the muffler pressure to equal carb inlet pressure, regardless of fuel head. Until you try it, you won't think it works. I was the same way. It's not specifically fixing a siphon effect, it's fixing fuel pressure variance due to fuel level. Any remaining "siphon" effect is not noticeable to me.
The Savage was notorious for half tank leaning. So much so, that it makes the truck almost undrivable. Set it for a normal tune near empty, and once you fill up the tank it richens to the point you can't get it to shift gears. Set it for a normal tune at full, and it leans so bad near empty that the RPMs hang, you can't get the clutch to disengage. Overheats, Etc..

I agree, I wouldn't believe that mod works unless I try it. It shouldn't work, anyway -- the exhaust pressure inside the tank should be exactly the same no matter where the exhaust pressure inlet is located, since the exhaust pressure will always distribute itself evenly across the entire internal surface area of the fuel tank. If the "uniflow" mod really does work, there must be some other explanation that I can't think of at 1:20am on Saturday morning.

I'm amazed you can still run your Bullet with such badly-worn drive cups. Mine started breaking dogbone pins before the divots on the sides of the pin slots got anywhere near that large.

At some point I got some knock off drive shafts and axles off ebay, and haven't had an issue since. I should also clarify that the groove cut into my drive cups is not just a thin groove, its wide enough to accommodate the sliding of the pin as the shaft rotates at an angle. The pins still have, more or less, a decently flat surface to slide against. There's some curve of course but not enough to bind it up.
Another thing that helped keep the truck from breaking was getting the traxxas 3.3 out of there and going with an O.S. 18cvrx which is much more tame.

I redesigned my intake and exhaust on my FS62-V powered Losi 8ight-t.
The intake is copper plumbing parts, soldered onto a flange I made on the lathe.
The exhaust is a brass adapter I made on the lathe, with 3/8" .020 wall stainless tubing bent to fit. It's brazed into the adapter. It swings around, into a standard 2 stroke pipe sitting in the factory location. Much better than having an airplane muffler sticking out of the truck to get destroyed. Also with this, the body fits now without hacking it to pieces.
Yes, it's a two stroke pipe. No, it doesn't hurt anything. My highest peak RPM and peak MPH were on this pipe a while back. 20,500rpm at 46 mph.

+ YouTube Video

I thought about making a carb adapter like that, but I lack the machining capacity. Good to know it works though; I had wondered whether it would be rigid enough and/or cause throttle lag.