It sounds like you have already answered your own question...

If you don't mind that the numbers don't match (or even prefer it)
then why should you care what others think? You can buy a garage queen
with perfect paint and matching numbers or you can buy a cool car to
drive. Each to his own.

It's your car.  Do whatever you want.  I like to drive mine, not sit around
and look at it.

I have a friend just about to start on a fuel-injected '63 split window he's
had on a lift for years.  He thinks he's going for NCRS on this one (he has
a finished '62 he's been offered $60K for).  I can't blame him, it's a
pretty rare car, but all that work and then to be afraid to actually drive
it...not me.

AJM
'93 Ruby coupe, 6 sp (both tops)

Matching numbers are important to many people including the magazines
that list the values of Corvettes.  However, there are some folks who
dont really care too much about matching numbers and would forego that
in order to get far greater performance out of the car.  Its really a
matter of individual preference ;  personally...i think the ideal is to
find a matching numbers engine that has been built-up to be bulletproof
; but that is my preference.  My 1970 BB from the factory is rated at
390 h.p and 500 tq ;  I opted to have it built up to 540 h.p and 600 tq
(according to Edelbrocks Dyno Chart).  Its a bit insane for the street
but oh..what a thrill to be slammed back in the seat.

Matching numbers matter in places where judging matters, like NCRS and
Bloomington Gold.  So if you go for that, then it matters.

HOWEVER, be aware that matching numbers does not mean original.  This is
very important.  Original usually means it is worth more.  Matching numbers
means that the overall of the car, the quality, and authenticity must all be
weighed in to determine its value.

IMHO, taking an original car, or even a numbers matching car, unless you
know the numbers have been faked, and turning it into a non-matching car
with a non original engine, extra performance, modern parts, and so on is
foolish.  If you want to build a performance car (racer or tourer) out of an
old Sting Ray, find one missing the engine, with an NOM, one that someone
has customized, and so on and build from there.  You lose less money that
way.

In terms of value (based on cars of equal condition), the original is worth
the most, the numbers matching second, and the customized (whether body or
mechanically) is last.  The exception is if you go full hog with a Pro
Street type build where you drop $100,000 into the car.  In that case, it
will be worth more than the original usually, but at what cost?  Often while
they may sell higher than an original, they still sell at a loss compared to
what you spent to build it.

I.e., Original '63 fuellie - $80,000, numbers-matching - $65,000, NOM
performance - $50,000, body customized - $40,000, Pro Street - $100,000 (but
took $150,000 to build).

Now don't look at those as true values of all '63 FI cars, this is just an
example of how the prices can vary.  Actual car prices will vary all over
the place, depending on the condition, the quality of work or restoration,
options, etc.

So my advice would be instead of finding an original base engine, PG car for
$50,000, find a semi custom (slight fender flares) with NOM for $35,000 or
less, and build it.  Even the work to return stock body lines will be less
than the $15,000 difference.

My motto: Save the originals, restore the important ones, preserve those
that survived, and enjoy the rest however you want.

BTW, the TH400 is going to require cutting the tunnel and the crossmember.
The TH350 will fit in the same space as the PG. The current thinking is to
use a well-built THM200R4 as it pretty much fits the same as the PG and
gives you overdrive on the highway.

If you look around, you can find one built that way for much less than you
can build it for.