Slight quiver when running?? 01 blazer 4.3 all is new!!!please help!!!going INSANE

USA spec car or?
no engine told of many
the VIN + RPO list at GM shows what is there.
RPO is the as built list from GM.
2000 blazer you meant S10 blazer right>?
this engine L35
1996-2002 - 4.3 L (262 cu in) Vortec 4300 L35 V6, CSFI,
if both are L35 sure. (assumes sub component accessories can be swapped too. if need be. (bolt on parts to engine)
engine swaps have 3 paths
block only
block and heads
block + heads and all parts attached.

it has to fit bolt on, and the PCM IN THE TRUCK (BRAIN)
must like all that, in all ways. displacement , firing order, and all accessories, related to EFI the alternator and HVAC parts.
IMO. join a real chevy forum that does this?
see all the pit falls there, our web site is not about swaps.

LIKE HERE>

https://blazerforum.com/forum/engine-transmission-35/02-chevy-blazer-into-01-gmc-jimmy-engine-swap-97344/

YES, u may have another problem but the answer to your question is you will get a misfire

Chevy Blazer Engine Swap Part 1 of 2 - YouTube

? 10:29
https://www.youtube.com/watch?v=Dt_7AKP2WcI
Aug 13, 2011 - Uploaded by Dave R
Replacing the engine in a mid-size Chevy Blazer 4x4 with oneout of a Jeep Cherokee 2wd. Original engine was low and motoroil and spun a bearing. ... Chevy Blazer Intake Gaskets Replaced & Cooling System Rebuilt - Duration: 16:45. by ... 4:02. 94 4.3l Vortec V6 GM (black motor) - Duration: 6:01. by ...

4.3 vortec engine removal - YouTube

engines come 3 ways, short block, long block or with all , including manifold., so ? which is it?
USA? we cant guess country , so will wild guess this as USA.
the dealers are gone.
so you cant just go there, online and see the whole engine and all parts there.
the engine exchange people know that, why not ask them
or just look at the many sellers on line of rebuilt engines.
modifications are huge. potentially.

• smog.
• added mounts. (for newer egr parts... yes, smog) or more....!!!
• upgrades.
• moved filters.
• new heads
• new oil pump designs.
• endless list here.?

to find out history why not join a real Isuzu form and ask.
some people keep records there of this topic.

Is it possible the replacement engine has a water pump that turns the opposite direction from the original ?
The thermostat has to be open to allow flow thru the radiator, have you tried running without a thermostat to check flow ?

If you have a cracked block, then you have a few options. You could find a used engine from a salvage yard, or you could order a rebuilt engine. If you did order a rebuilt engine then you would probably have to pay an extra "core charge" since yours isn't fixable. You should be able to find a used engine for under $500.00 and then the labor to swap the engines depends on the area you live in. I would figure about 12-14 hrs at the going rate.

It is the oil cooler lines that run to the radiator to cool the oil.
Go to a auto parts store, tell them your make model of vehicle, and they can get you a seal kit.
Please let me know how it goes.

Check transmission fluid with vehicle up to temp (after driving) and running at idle on level ground. If slightly overfull no problem. Be sure to remove dipstick, wipe clean and reinstall/remove for accurate fluid level check.

replace fuel pump inside tank