Rod bearing replacement in truck 3.4 ,4x4

I have been fortunate enough to have found some tacoma's , that needed tlc , were reasonably priced, and I have the reserve funds to get them, freshen them up , and sell them as a better vehicle.

The other day I got another 95.5 with 3.4 , manual trans, and it is a 4x4 .
After getting the truck running, had a cracked head , driver side center cylinder , I get a fairly significant tapping on first start up , for about 15 seconds , then goes away .
It will not make the noise the rest of the day, after the initial cold start.
Valve gap is within spec .
Engine has 269k miles, doesn't use oil , has decent power , and is really a solid engine, compression and leak down tests have been done , and vacuum gauge is steady at 21" .
Frankly, these engines especially today , with small pistons, rods stroke , bottom end noises are not like the days of old when a rod or main bearing being lose was completely different sound from a broken valve spring, cupped lifters overhead cams etc.
Only the old guys would remember those days.

The question I have is this , is it easy enough to remove the oil pan, roll in a set of rod bearings if there is a cylinder that has o e that is out of spec, with the engine in the truck.

I think the crank case was flooded with water, (had the drink of death when I got it ) and smelled heavily of raw gas.
The engine has excellent oil pressure as tested with a mechanical gauge.
Bearings are cheap, if I find there is significant damage to the journal , I would obviously pull the engine and do a crank kit.
The 3.4 engines here , asking prices for a used engine , are more than I can personally rebuild one for.

I am pretty sure it is not a wrist pin,, sound goes away after the first start, and is not rpm related, as in if I raise the speed it disappears,wrist pin would normally get worse as the rpm goes up.

 

Not 100% but I am pretty sure one needs to drop the front differential and lift the engine as far as possible to have enough room to get the pan clear of the sump.

On a stock vehicle

Then your working around everything as well

 

also I have heard the pans are murder to get off with that toyota sealant that acts like super glue bonding it together so tight you sometimes have to pry it off inch by inch then equally a nightmare to get the surfaces cleaned up to reapply.

I understand you not wanting to do extra work if not needed but you should pull the engine and get the proper access you need to investigate what is going on with it and have the room and access to things to do it right

 

Thank you for your information.
I am not convinced it is a rod bearing, could be an exhaust leak, crack in manifold ....
Ill be looking .