How far should I tear this down - 73 W100 400 block

The continuing saga of my 73 W100 that I'm trying to get roadworthy. I had some trans, driveshaft, and motor mount issues that I've dealt with already. The trans has been rebuilt with the correct tail case now I'm on to the engine. My previous thread is here but I thought it would be best to start a new thread.
https://board.moparts.org/ubbthreads/ubbthreads.php/topics/2912234/1.html

Pulling out the oil pan pickup I found all of this crud in the pickup screen. I'm assuming it's a collection of gaskets and valve seals. The crank and rods show signs of the oil being run long/burnt. Given where I'm at I'm thinking about taking the plunge and doing the following to avoid putting a possible problematic engine back in the truck. The engine ran ok, with some smoking when it first started. Oil pressure was a little under 20 psi at warm idle. No weird noises while running. No idea on the age of the engine, not sure it's original or not since there are no vin numbers on the engine pad.

Here is what I'm thinking -

New rod and main bearings.
New piston rings and ball hone cylinders.
New oil pump
New water pump
Replace all core plugs
Pull heads and replace springs, hand lap valves, have gasket surfaces on heads machined for sealing.
Of course replace all gaskets and new rear main seal.

Outside of time and money is there any reasons I shouldn't take this deep of a dive? Is there anything else that I should do?

Thanks in advance and Happy New Year.

Add new valve seals to the list, and likely valve guides too. At that point you might consider a valve job instead of just lapping.
Timing chain!

When i got my 78 it still ran but after pulling the motor to rebuild i found some of the cam lobes wiped. I'm surprised you didn't see the plastic from the timing gears down there. By the looks of it i would tear it down completely and see what you have. Gaskets, bearings timing chain/gear etc are a given for a refresh. Just an FYI watch out for those china made engine stands, I had fully loaded 440 on one and the weld broke dropping it on the ground!

Once you have it torn down this far you may as well go all the way tearing it down and fixing whatever you find.

Just an FYI watch out for those china made engine stands, I had fully loaded 440 on one and the weld broke dropping it on the ground!

Now are we talking about those Harbor freight deals ? Cause i was just looking into one of those deals

Inspect the item you are actually bringing home these days, doesn't matter where it comes from. Crap looking welds are usually crap welds. Not all the items in the same lot have the same problem, it could have been one guy on the production line. Probably 75% of a 25 years I was in the welding business was spent rewelding crappy welds on new stuff. If it has a round bead sitting on top of two pieces of metal, its not holding anything. It seems many factories put new people on the welding line that have no idea what they are doing, or they have to work so fast, they can't do it right. That disgrace isn't limited to just products from China, though they were pretty high on the list. Mexico, the USA, and Canada had their fair share of failures too, as did several other countries. Gene

Welp, it's getting completely torn down. I'll get the block hot-tanked. Absolutely filthy engine with chunks of debris all through it and cooling passages filled with gunk. The rags in the intake ports are from when I pressured washed the engine last spring.

Once I pulled the valley pan I quickly realized that completely disassembly was in order.

Good call. Once apart you may still get away with a cleaning and fresh rings & bearings. This is usually the point where simple turns to complex, the old "while I'm in there" takes over and things usually get out of hand quickly. Good luck on your adventure. Gene

It was nearly 40 years ago so no it wasn't HF but one of the china made stands. I got fed up with the cheap crap they sell and modded/built my own made from a hydraulic cylinder(round part the engine turn on) both inner and outer with brass bushings installed. It will not break!

That’s baked and hardened oil from around the heat passages and 2 oil changes in 50 years. Total hot tank, machine everything and all new parts. Don’t buy new clothes but keep your dirty drawers with the skid marks.

I had a stand in the early 90's break because the boxed channel iron at the bottom actually tore the metal. It was just a 304 AMC engine so it was not overloaded. Learned then if a stand doesn't have bracing and gussets it gets them before being used.

I always had a piece that supported the crank snout, actually two, one for when engine was upright and when it’s upside down. Helps on a heavy Hemi.

Those yellow pieces in the first pic, are those timing gear teeth?

They looked like valve stem seals

One of the heads has this issue with a valve cover bolt hole. The hole had some epoxy in it and was threaded to kinda hold the valve cover bolt. The hole is wallowed out and goes through to the water jacket.

So, can this be repaired or is it even worth repairing and I look for different heads?

The valves are somewhat mushroomed I had to file them a bit to get them out. The valve guides have pretty sizable side load wear.

I'd look for another set of heads. Otherwise, your looking at some welding and machine work to fix the valve cover bolt hole, new valves, new valve guides, and probably new valve seats. It looks like that motor was used pretty hard, or had a bunch of miles on it.

What are the actual stem guide measurements? I have seen them put back together with new seals and a fresh valve job run smoke/trouble free for years. For the thread repaiir:

I don't know, I don't have small bore gauges to measure the stem guides. Looking inside them though there is certainly uneven wear marks and some galling inside the guide.

I looked at those E-Z Loks, however they are hollow. Wouldn't I have a potential issue with coolant coming up through the threads unless the valve cover bolt threads were completely sealed?

The factory used a stud there. little jb/sealer and a small stud. It was probably a stud because of going into the water jacket. Like the exhaust.

In addition to being open into the water passage, it really doesn't look like the drilled hole was where it was suppose to be. If the hole is not properly located, then anything you put there for a thread insert will not match up to the hole in the VC. The through hole looks to be more then 1/4 of the bolt diameter off from where it looks like it should be to me. Setting a good valve cover on the head would confirm the position of the hole being off far enough to cause a problem or not.

you have some work ahead of you by the looks of it

Those iron heads are a dime a dozen , I'd start with another set, what part number heads do you have ?

Hey John how are you? Haven't conversed in a long time.

Welp, the horse has left the barn on this. I took everything into the machine shop, an old school mopar-friendly place, and the block needs bored and instead of putting money into iron heads decided to go with some Eddy E-Street heads and be done with it. Crank needs turned, the bearings were well on their way to being toast. So tearing it all down was a good idea. Was an incredibly filthy engine.

I'm doing ok , finally getting back to start working on all my dormant projects and to thin down my junk collection after having to move it all out of my basement after the town sewer backed up into it ...ugh .

That was probably the best idea to go with the e streets, rebuilding old iron heads isn't cheap , money well spent . Pay attention to the pistons you buy , off the shelf for stock stroke 400 choice isn't that great, you might have to get something from someone like Diamond? a possibility also is to look at replacement 440 pistons. There is a smogger piston that is is in the 1.9 CH range that will get you close to zero deck , you might just need to add some small valve reliefs depending on the size cam you chose.

Actually an easy fix. Hardest part is locating where the hole should be. Have it drilled for a 7/16"-14 thread then tap thds in, get a bolt or some all thread drill the end for 1/4"-20 thread. Cut the threaded end off to length needed to be flush or below surface. screw in a 1/4" bolt with a jam nut on it using red lock-tite on the 7/16 threads. Walla done. Just make sure the insert is flush, maybe file it flush.

The ship has sailed, I bought E-street aluminum heads. My heads were toast. Just got everything back from the machine shop. .030 over and .010/.010 on the crank. Time to start putting it back together.