This thread will be a rough collage of pictures about the slow fixing up of my 1967 Cadillac.

 

I wanted to get the seats out to be reupholstered in January, found out we had to have windows down or doors off to do that, but the windows weren't playing nice.
I decided to start with the rear passenger door window for logistical reasons, found that the connectors at the window motor are prone to allowing moisture to rust the terminal, and they also are very brittle and therefor are almost impossible to take off the motor plugs. Got them off, destroyed the plugs and wires, so I cut the harness terminals and cleaned them, and I used a grinder to grind down the motor's male spade terminals until I found semi clean metal, then I did the worst job soldering the female and male spades together to hopefully encourage a better connection. I then doused the entire "area" in a copious amount of hot glue to keep away the moisture, we'll see how that remains durable.

The connection was better, but not perfect, good enough for this neighborhood; the window went down and out the seats came.

 

Now in May I was finally able to move the vehicle to my location and I am going to need to swap in a newer Cadillac 500ci engine from a 1975 car. Beforehand I am going to try and test-run the engine in a test stand I haven't built yet, then swap it into the car. I'm currently installing a new timing set, replacing the front and rear main seals, and considering replacing the valve seals, but that's a big maybe. Obviously Viton is the way to go but from what I remember normally you have to specially machin valve guides to accept modern Viton seals, that'd mean disassembly of the head/engine--no deal.
My progress so far:

I am 1) an idiot, and 2) working with a new brand of engine I've never worked with before. So I tore the oil pan and timing area apart quickly and forgot the order of things. What I learned/am learning:

• The timing cover is reassembled FIRST, then the oil pan. I messed that up and wasted my oil pan gaskets.
• The bolts for the cam sprocket cannot stick out of the back more than maybe .020": I didn't measure them but I think one is sticking out .014"(sarcastically) and now I'm contemplating wasting my timing gasket set and tearing it all apart to make sure the bolts aren't sticking out too much. I stuck a camera in there but all it shows is blurry and undefined...

Once that's all done and before the engine can be fired there is a bolt hole in the intake manifold for an A/C bracket that stunningly goes directly into intake passage #5, but someone stripped it out partially and when testing my A/C bracket, I finished the job. So now to ensure there are no shavings in my intake, I get to install some weird Fel-Pro(MS96028) metal valley pan gasket which looks like a whole lotta fun.

Yes I know it looks like the timing is a tooth off, but when the chain was installed they were perfectly aligned, and that picture was actually taken after I moved the crank to "take up the slack", to be shown to an engine builder friend to see what he thought of it, I'll ask next week.

 

The Cadillac 472/500 have the smog passages built into the heads and are plugged in the rear of the engine but use some kinda of plumbing system in the front--which was removed at some point. All four corners were open and leaking in some way.
I found that Dorman 555-082 expansion plugs fit the bores and plugged them today.
The engine gasket kit came with two very odd and brittle chrome looking rings. Come to find out they are for the plumbing to two of these holes--but if you are plugging them with plugs the brittle chrome rings are not needed.

 

You Tube

Had a 76 Sedan Deville once upon a time, it was a beast with that 500 in it. Found this set of caddy 4 note horns on ebay, put them on my truck, no other horn has that signature, commanding sound.

 

So on a whim I decided to replace the valve seals. I rented a tool from Oreillys for about $30, after a couple valves it became easier and faster. The new valve seals are simple "umbrellas" and made of relatively hard brittle plastic which surprised me, but it should do the job for a few months or year which is how long I need this engine to last before replacing it. The old seals were brittle as glass and most fragmented, especially on cylinders 3-6 which are adjacent to the exhaust crossover. Lots of crud which I believe is superheated/cooked oil around the valve areas of those cylinders as well.

 

Unfortunately After replacing 6 cylinders of valve seals, on the 2nd to last cylinder(which was actually cylinder #3) I got a cute little surprise.
On all the previous cylinders I used about 40-50psi of air pressure to keep the valves up whiles the spring assy was off and this worked fine, but oddly enough on cyl 3 the valve would barely stay up even with 100 psi, but if you even looked at the valve wrong it'd fall down--the cylinder wasn't holding pressure. I wasn't expecting this and decided to do a leakdown test with a tool provided to me by a machining professor and friend.

I want to be clear this engine was bought used and I knew very well it would be a temporary engine until I could build a new one in 6-12 months.

But the results were poor. Two out of 7 tested cylinders had passable 25% leakage. The other 5 tested cylinders had abysmal 50% leakage, one of them actually had 60%. You can hear the (mostly exhaust) valves hissing air past their seats. I was told by my professor friend the obvious: seats/valves are cooked and will only start leaking more until you totally burn one.

I am still deciding on a plan of action. I need this engine installed in the car ASAP so I can get a new driveshaft made so I can take the car on a test run to see how it will drive. Can't wait on a machine shop for 5-10 days to do head work on an engine I considered disposable in the first place.
I am leaning very far towards install engine immediately and pray it gets me 3-6 months.

I'm just posting cyl 1-3 for fun.

 

In '68 or '69 the heater hose line came off of a small nipple underneath the thermostat housing; sometime in the early '70's they did away with that location and used a giant 1" NPT nipple out of the rear of the passenger side head(odd cylinder bank). Getting that off was a pain, I ended up welding it to super-heat it, then let it cool and broke it loose with a 4' breaker bar.

 

That giant 1" nipple can make swapping the engine harder, and it's simply not in a good place. Scott Hatch on youtube does a bunch of cadillac 472/500 information videos and highlights that the cylinder blocks casting boss for the original fitting in '68 is still there and you can simply plug the 1" hole in the back of the passenger head, and drill/tap the boss underneath the thermo housing for the heater hose routing. I had a 3/8-18 NPT brass fitting laying around and a couple taps for that thread so that's what I went with. You should drill this with a 37/64 drill bit but a close second is a more common but slightly smaller 9/16. This was almost a mistake, getting near the end of the tap was getting very difficult even with an 18" cheater bar and lost of Rapid Tap cutting oil. My advice is to go with a 37/64 drill.
I drilled using a 1/8" bit, then moved up to 5/16", then to 3/8", then jumped to 9/16. It was a bit arduous but it wasn't too difficult.

I was surprised by how thick the metal was at the boss under the thermo housing.

 

I took the passenger(right) exhaust manifold off to replace the gasket in case of a leak and the engine was already out but that was a mistake, it looked like there was no leak between the manifold an head, but there was obviously a leak between the manifold and an emissions device and where the pipes connect.
Several bolts broke in the head and I spent three weeks slowly spinning my wheels to no avail.

ALmost every "remove stuck bolts INSTANTLY!!" youtube videos showed someone removing a bolt that was very clean and nice inside of the threaded hole. My bolts had a ton of rusty powder in the bolt holes and threads, I believe this is what caused a "gridlock" effect and even if the bolt broke loose, it would quickly get stuck again and break again. I eventually just drilled all the broken bolt holes and tapped them with a slightly bigger metric thread which didn't work because I wasn't smart enough to figure out how to drill the holes perfectly on center. I ended replacing the original 3/8" bolts with smaller grade-8 5/16" bolts that have a nut on the back and tightened them down enough.
I probably ruined the head drilling everything wrong but this engine is tired and it's days are numbered. Someday someone might find this engine in a junkyard and see the crazy bolt system for the head and wonder what idiot did this. I've seen a lot of that in junkyards myself.
First pic shows bolt rust dust causing gridlock
Second pic shows my pathetic attempt at replacing the studs for the collectors
Third pic shows the collector bolted to the emissions thingy, which both studs for that were also totallyfrozen, one was eventually drilled out.
fourth pic is terribly finished product, keen eyes will show different bolts and nuts placed near the spark plugs.

 

Now it was time to try priming the engine oil and installing the remanufactured "CARDONE" HEI distributor I got from rockauto.

The tool I made is a 5/8" deep impact socket and an 8" extention. I cut up a small double open end wrench(1/2-9/16) and used it's shank as the tooth for the oil pump shaft.
Spinning at a reasonable speed I could only get 40 psi, good enough. (Later I'd find With the engine running I only got 45-50)

The distributor was installed and I got as close to 12º BTD as possible for initial static timing(advice from Scott Hatch youtube video), and nothing happened when cranking engine with the starter. I'd eventually start enjoying the experiencing of an apparently common issue today--bad out-of-the-box HEI ignition module). I have never actually been inside of an HEI so everything was new to me and took me a week to figure out. Payed $47 for a Standard LX301 module at Oreillys and that solved the problem. Engine fired right up using a junkyard Quadrajet I had marked "Blazer", the numbers have it for a '75 Chevy truck, probably 350ci, the venturi bore dimple shows it's an 800 CFM variety.

As far as "parts that are becoming regulare failures out of the box" goes, from experience and reading on the internet, I guess we can surmise: You can't trust brand new cams/lifters, you can't trust brand new rear diff ring/pinion sets, you can't trust new Qjet accelerator pumps that come with basic rebuild kits, and you can't trust brand new HEI ign modules. Let's see what else we can't find.

 

July 16 2025 I need to start swapping a newer Cad 500 into an older 1967 body/frame which originally had a Cad 429 and the older version of the TH400 which uses a different bellhousing. The previous owner removed the engine many years ago and never progressed further, but that would've left the transmission hanging there with nothing to support it near the bellhousing, so they made a home-made crossmember that used two bent bolts that stabbed up into frame rails and that's what held the original trans in place. Good idea, and I'll reuse it when installing the new trans.

I jacked up the passenger side of the car a foot high so I could remove the old trans and install the new one to let it hang there until I swapped in the motor later on.

 

I called a Cadillac parts place and asked about swapping the 429 from my '67 DeVille to a 472/500 and they had some accurate info: Drill the main engine crossmember holes ~1" forward, center to center; and the oil pump will hit part of the frame.

I decided not to listen to them and see what all the fuss was about. I first tried installing the engine with the crank and water pump pulleys installed--nope, it hit the main radiator support in the front and the fragile AC box and "Vacuum modulator" in the rear. Tried removing the pulleys, not any better.
Got a tape measure and realized even if the engine was completely level and if the Modulator was removed, I'd still have less than an inch clearance.

You can swing the engine to make way for the oil filter, but the pulleys make it really difficult, and maybe impossible without removing the AC stuff.

 

I spent a couple hours weighing the options and decided to cut off the radiator support.

I first made brackets that I will use to me sure the rad support goes back in aligned correctly, by drilling the holes to 3/8" and using 3/8" bolts, so they "index" the bracket and support with eachother to the exact location they originally were.
I then cut off the support. It was a good decision in my opinion, made things far easier and saved me from spending forever unbolting the entire front clip and then having to find a place to store it, and then having to spend forever reinstalling it.

I circled in red where I drilled four 3/8" bolt holes to be used as a "perfect fit" index to make sure the support would be bolted in perfect. I may weld the brackets I made for each side to the middle of the radiator support. The brackets I made are roughly 5" long.

Second pic after the cut.

 

So now I could actually lower the engine into place and start addressing the engine crossmember issues. I allegedly need to drill the main engine crossmember holes ~1" forward, center to center; and the oil pump will hit part of the frame.

I completely cut off the upper passenger welded frame brace, and intend to weld it back in slightly moved over. I had already cut out chunks of it before I realized I absolutely must move engine forward 1"--when I set the engine in the original bolt holes, it didn't completely interfere so I only cut what I needed.

I don't enjoy drilling large holes in thick metal in awkward places so I opted to hack it away with a angle grinder and fill in the holes with what I cut out and weld it.

This took a total of 3 engine installations. 1) into original crossmember holes--too far back and needs to go 1" forward.
2) After cutting the holes larger, so I could test fit.
3) Installed engine a third time after welding holes shut.

I personally believe from what I experienced that you need the engine moved 1" forward to allow room for the trans bellhousing to rise enough to help get the right engine/trans angle. Cadillac made these cars from the factory with a significant "lean" backwards to the engine so they could lower the driveshaft and lower the floors--from what I've been told.
The oil pump/filter was about 1/32" away from the swaybar with the engine in the ORIGINAL holes--but it wasn't touching, you just needed to edit the front frame brace.
But moving the engine forward gives more clearance to the oil pump from the sway bar, however it require you delete that front frame brace. It also gets the oil pan to within 1/32" of the front sway bar--close, But I'll live. There's actually enough slop in the bolt holes and driveshaft slip yoke where I could probably move it back to give me 1/8" of space between the pan and swaybar--I'll do that if necessary.