The only "spincast reel" that should be on a "spinning rod", is called an "underspincast", I have a Daiwa version..p.o.s., imo....lousy inconsistent line pick-up.
Trigger grip(baitcaster) rod for the "202", "33", "66", etc. by Zebco, & other models, otherwise you'd lose your grip on the whole affair, when your thumb quits gripping and moves to push the button for release.
No need for a larger "first line eye", since it's coming out of a 1/2" hole, rather than a spool end that varies from ~1 3/4" (size "25" or smaller) to as much as 2 1/2"-3" on a surf reel in a size 6500 or such. My larger spinning reels on my surf rods definitely need that 2"+ first eye, just to accommodate the line's ability to "clear the spool lip" when casting.

While we are on sort of the same subject... anybody have any experience with the rods with "spiral" line guide placement ?
As in, starts on one side (top or bottom) and ends up 180° from start, by the time it gets to the tip. Have seen a couple advertised, but not in person and curious about advantages, if any.

Well that's funny, I agree with both those comments. You need to clarify what a "spincast" reel is. Do you mean a closed face reel like the one in the first photo, or an open faced reel like the second? The first? Yes, like RJS said - that's what it meant to go on. Second? Not advised, but yes you "can". Several reasons not to. Like catfish hunter said - that first eye on a casting rod is way too small and you're not going to like the problems that that will cause you. Also, when a rod is built, the eyes are placed on it to match up with the natural arc of the blank - casting rods on the top of that arc and spinning rods on the bottom.
So my answer is - yes you can if you have to. But you really shouldn't, they're not made the same way. It will work, but not very well.
BTW - that first photo is of a spincast reel. The second is a spinning reel.

Well that's funny, I agree with both those comments. You need to clarify what a "spincast" reel is. Do you mean a closed face reel like the one in the first photo, or an open faced reel like the second? The first? Yes, like RJS said - that's what it meant to go on. Second? Not advised, but yes you "can". Several reasons not to. Like catfish hunter said - that first eye on a casting rod is way too small and you're not going to like the problems that that will cause you. Also, when a rod is built, the eyes are placed on it to match up with the natural arc of the blank - casting rods on the top of that arc and spinning rods on the bottom.
So my answer is - yes you can if you have to. But you really shouldn't, they're not made the same way. It will work, but not very well.
BTW - that first photo is of a spincast reel. The second is a spinning reel.