Yes. There are thread repair kits. Helicoil and the like.

Can i leave it as-is, with all

In theory, no. In practice, I've seen it done but only on engines that
never ran at full power. And they ended up self destructing after a few
years anyway. (Not necessarily from the head not being on enough, it may
have been that overheating wrecked the threads AND caused other problems).

You'll need to remove the head and repair the thread.  Helicoil type
inserts are the go... you can either buy a kit  and do it yourself
(Recoil is probably the most common brand) or have a machine shop
(engine reconditioner) do it for you.

wouldn't be handy if you striped the bolt,pretty unlikey with cast ...lol

Blow between....not a great idea,its possible,you may run into
problems,normally there are only just enough of those head bolts.
Then again with 20 plus bolts to the head,you may be in luck.
Leave it out and try it,as long as it don't look like the head is going
to warp,even though it possibly will a bit,you have not much to loose.
It may runs for years.
If you were just retension and not replacing its your best shot to leave
it there without the bolt.
could be lots of fun if it fails while on the water ...lol

Helicoil works,hate em but they they work in places like that...off
comes the head.....

Pull the head off and have someone helicoil the stripped hole.

Not if you ever want it to hold a head gasket properly.

Not for a stripped bolt you won't.

A helicoil will take care of it in a jiffy and work just fine, and the 7/16"
UNC kits can be had over the counter at most auto parts outlets or bolt &/or
bearing suppliers, but it's not something I'd recommend you do you're not
competent at cutting threads straight. Take the block to your local mechanic
or engine reconditioner and ask them to throw one in for you, as it only
takes a few minutes.

If you plan on keeping the factory bolts and using them often, then consider
helicoiling *all* the head bolt holes, or, better yet, get yourself a top
end stud kit and throw the standard head bolts in the nearest bin.

--
Regards,
Noddy.

Have you removed the stripped bolt?
Maybe the bolt is damaged and the block is OK, the only way to know is
to remove the bolt.
Even if its just the bolt you will probably still need to remove the
head to clean out the thread but that isn't a big deal and will only
cost you a bit of time and a couple of gaskets.

Helicoils as others have mentioned.

Can i leave it as-is, with all

Bad idea.

Very unlikely.

Daryl

Here's the thing - nobody is pointing fingers because you stripped the
thread, but torque wrenches don't need breaking in. They are supposed to
be tested and calibrated before being sent out from the manufacturer,
and if they needed 'breaking in' they couldn't possibly check them.

There's something wrong with the torque wrench. At best it had been
sitting for years and had seized a little (unlikely) or it's got a fault
and somehow made it through quality control (which is close to
non-existant if it's made in china).

In my honest opinion, it's one of the few areas not to penny pinch. You
can get away with less than ideal breaker bars and ratchets, but sockets
themselves should be as good as you can afford (and I note that not all
are available individually, but you get my drift) and torque wrenches
are another area.

At the very least, enquire at your local repco or tool specialist if
they can get it calibrated for you (actually I'd seriously suggest
taking it back, with stripped bolt and demanding a refund or
replacement, the former preferably. I'm not even going to joke that
they'd be keen to give you a helicoil kit free, but they should
(whomever you bought it from) at the very least honour the warranty.

You're hardly the first. The fact is the block isn't new, and it's been
through who knows how many builds and heads and owners. I remember one
engine I helped a friend with (that pretty much ended the friendship,
and it wasn't all his fault) due to stuff like that.

The last straw was when just about to start it and run the cam in.
turned on the starter, the motor kicked back a little (timing was as
close as we could get without actually starting it!) and thje starter
motor ripped out of the block. both those threads had only a few mm that
weren't ripped out, and it 'seemed' fine when bolting it in (I'm
generally not one to overtighten) but tjhat was it- on it's last legs.

Take the bolt out (it'll be ok to do that with the others left in at
whatever tension they are, but _don't_ try and run it like that.

heli-coil

They are 'magical' . basically the kit comes with a special tap. After
drilling (hence you need the head off to do this and tape up the bores
and all other holes too, to prevent metal shavings getting anywhere)
with the right drill bit (they list the right size for each helicoil,
and measure with a micrometer or vernier, don't take the size stamped on
the drill bit as gospel - and it's the one time that this measurement is
absolutely vital) you then put the tap in and it will cut a new thread
that's a special oversize.

then you wind in the helicoil - it's like a spring, with diamond shaped
metal. It winds into the new thread that's cut then on it's inside it
ends up as the size of the original bolt thread. A perfect repair
(there's a touch more it, but that's the basic rundown)

Properly done, a helicoiled insert can be stronger than the original
thread. That's on cast iron. It's more than doubly so on alloy. On
volkswagens they used to have threads in teh alloy cases. and they used
to rip out. They used helicoils to fix, and soon enough the factory used
to actually make the blocks and fit the inserts there, as a matter of
standard procedure. They weren't generally called helicoils, they were
referred to as case-savers. Lets you know how good they work.

Also - I second Noddy - bolts going in and out of the block all the time
will wear it down. It's far better to run studs. Then you screw them in
(just a nip past hand tight) and tension via nuts at the top. That way
only the nut turns on the thread of the stud, and the stud in the block
doesn't move, so it only wears the stud top thread and the nut. It'll
generally last a number of rebuilds, but even if it didn't, you can
replace the studs, and the threads actually in the block suffer zero
wear.

Even if all of the head bolt threads in the block were stripped, you'd
be able to save it. the helicoil kits come with about 10-12 helicoils
(and the tap and installation tool) for the price, and you can then just
buy replacement coils themselves. It wouldn't cost _that_ much to do a
whole block if need be.

Having said that, I doubt it would be necessary.