Heater core by-pass procedure 96 Cadillac sedan deville w/northstar

A hunt and count question. core/freezed plug.
NO VIN told no RPO code for engine told.
8th digit of VIN is ENGINE CODE VIN :"Y" below.
or vin=9 (8TH)
well even the service manual does not do the count.
it shows some, block and heads.
what you can learn to do is google it.
here is how to do that
I google new rebuilt raw engine blocks for sale.
watch out engine can evolve and even be swapped a newer GEN engine, 279 cu in (4.6 L)
but I will post for DAY new,1996 only
1996, the Northstar engine
RPO code LD8 or L37
lets to LD8
the DeVille Concours was available with the new 270 hp (201 kW) LD8 Northstar V8, and later, the high-output L37 Northstar generating 300 hp (220 kW).
LD8
first hit shows VIN-=Y shows 4 in the 2 heads 2x2.=4
left and right heads outside ends. and 1 rear and front of head for 6 total,

https://www.npdengines.com/product-page/96-99-cadillac-deville-4-6-northstar-engine-vin-y

found with google
die-cast aluminum block!!! SORRY NOT SAND CAST.

A GOOD TECH FINDS THE ACTUAL LEAK FIRST
SEEMS YOU ARE GUESSING,
THE 1995 BACK IS ALL DIFFERENT.

LOTS OF VIEW HERE, ALL FOUND VIA GOOGLING FOR YOU.

https://www.hpmotors.com/cadillac-northstar-v8.html

FIND THE LEAK FIRST, THEN WORRY CORE PLUGS IF AT ALL.

Ours was delivered new with a cracked block. Was fine after replacement.

Is your floor wet on the passenger side up front and smell like antifreeze? If so, the heater core blew, but it's not hard to replace.

Assuming you have the Northstar engine

do the heater core coolant supply hoses both get hot at the firewall in the engine compartment? if yes then you have a defective temperature control blend door actuater motor.

the belt is on back of head,no hard to do.remove cover,release tension, by pulling back on tensioner.
with car off grab belt with your hand and pull,this way you can see how tensioer releases tension.

Yes you can. 2000 Cadillac should have a northstar already in it.

Take both heater hoses off and hook them together with a piece of pipe and a couple of hose clamps.

The heater mabey cause from many things easy to check are your thermostat. heater core or low antifreeze

I do think you have to pull he dash, for that you will need a manusl, try ebay for used factory manuals, I have had good luck getting them there for all my cars.