Is it possible to fit bolts in a stock 27 fever with 496 for lifting her with slings and hooks, instead of external slings under the hull?
I guess the bolts could be screwed beside the engine mounts maybe?
I also noticed that there is already an eyebolt inside the anchor locker, but it doesn't seem strong enough for lifting.
Or is it, considering that there's not much weight in the bow?
Any views/experiences highly appreciated!

When I did my bottom work, we used the three lifting eyes. That's what they're for. Use some good mil spec nylon soft straps that won't scratch. Put towels under them against the gel coat and lift. The eye in the anchor locker is NOT to be used for lifting. Use the bow lifting eye and the two respective eyes on the transom. A couple of mid sized gantries or forklifts will work fine.

Mine had the engine out. Put some tires under the boat if being left in the air for a while. In case it falls a short distance, tires or something like tires would soften the blow and give you better means to lift again if something happens...

Do you mean the two U-bolts on the transom (above the flaps) and the one below the anchor locker (on the other side of the eyebolt I was mentioning)? Geez, I wouldn't even dare calling them "lifting eyes", particularly astern!!!
I mean, they're surely strong, but they're actually just meant to secure the boat on the trailer, aren't they?! And not just in the Fever 27, btw: that's what they're for in ANY boat, afaik - not for lifting.
I guess they're ok for the odd boat moving with the engine out, but what I'm looking for is a way to regularly lift the boat with two straps secured astern and one upfront, instead of using the slings under the hull.

Use the bow lifting eye and the two eyes on the transom. A couple of mid sized gantrys a few yard alarms and some styrofoam blocks .. piece of cake

Mmmmm... Wadduthink of the concerns I explained in my previous reply?
Maybe I'm too worried, but I've never seen any boat, also smaller and lighter ones, lifted and moved around just using those U-bolts, in any marina...
And I prefer to be safe than sorry anyway - she has to be lifted 8 feet or so above a concrete floor, when moved back and forth from her shed to the water!!

Whats wrong with the current method?

You wouldn't call them lifting eyes because you don't really know otherwise. I didn't save my photos of the boat hanging in mid air for over a week by those 3 points. But if you want to use the one in the anchor locker my bet is that it won't make it off the trailer..

if she swings she strong....if she breaks she,s gone.

Nope, actually I just mentioned it 'cause it has a weird shape, different from the plain bolt normally used to secure the anchor chain - hence my guess that it could be a lifting eye.
But my concern is mainly for the transom bolts, where most weight is: I wouldn't have expected them to be good enough for lifting the boat...

And in reply to Wildman_grafix, nothing really wrong with the slings under the hull, but when positioning the boat on its cradle they remain "locked" between the hull and the cradle.
To remove them, it's necessary to use another sling to lift the boat astern a bit.
The three straps method would be much more efficient in this respect, if those U-bolts are really strong enough.
The point is... are they?

Yes.