[big_gto]

Anyone swapped a Cadillac 500 into a `64-`67 Tempest or Lemans? A stock `70 500 makes 400 hp & 550 lbs-ft of torque.

[Donovan]

I remember a long while back someone posting that swapped one into a 68-up. I recall him saying it was not nearly as easy as people make it, and he was searching for a hood to make room for it or was going to sell the caddy engine.

search the archives

[455HOGT37]

I put a 500 in my 68 ElCamino and have been driving it for many years. It requires a bit of fabrication and some parts substitution, but it is not all that tough. The hardest part is the engine mounts. The Caddy mounts are way forward on the block, so frame "spurs" need to be welded to the front side of the cross member. If you have power brakes, a late model booster will be needed (smaller diameter) to clear the valve cover, and if you have the hide away wiper option, the valve cover will have to be dimpled slightly. If you have air, the suitcase will need to be clearanced and fiberglassed to clear the valve cover. Finally, you will need to fabricate or buy a true rear sump oil pan (the Eldorado pan is a mid-sump). With the stock intake, a 1 inch spacer, and a 3 inch drop base air cleaner, the stock hood fits no problem. If you run an Edelbrock manifold, then I'm not so sure. The Edelbrock does eliminate the possibility of stock air and power steering though. Stock Caddy exhaust manifolds fit the chassis (tight), and BBC headers can be modified to fit the engine with available flange adapter kits. Lots of other info here: http://www.cadillacpower.com/forum/index.php

[JB 472]

Big,

That would be me.

I am putting a 472 Cadillac and THM-400 into my '65 Tempest Wagon.

The car is being built as a drag racer; S&W back-half, Dana 60, full roll cage.

The big Cadillac presents several problems for a swap into a '65 Tempest. It is not a big block Chevy (BBC), shares nothing with it. The Cadillac distributor is in front, leaning over on the drivers side. Think mirror image of a big block Mopar, external oil pump and all.

Three major issues to deal with:
1) Motor mounts. As mentioned above, you will need to weld horns to the front of the crossmember to put the mounts out where the Cadillac has them, at the very front of the block.
2) The bore spacing is 5.0 inches on the Cadillac (the only thing stock on a Pro Stock motor is the bore spacing and it is a Cadillac number, not Chevy). That means the headers do not bolt up. I have heard on people bending the tubes to fit, but realistically you will have to cut the headers up and reweld them. 3-D spacial geometry comes in handy.
3) The cylinder banks are offset opposite of the BBC, meaning that the passenger side is slightly ahead of the drivers side. This messes up the header build-up two ways. The passenger header downpipes have to be run way aft before they can go down and they go down right at the starter. An aftermarket geared starter is a must. The second thing is the suspension. Upper A-arms, the pivots, and the pivot mounting bolts are all in the way of the first two pipes. Major tweaking is required here to get everything packaged with clearance.

Definitely doable, but not a weekend project. I spent seven months of weekends building header flanges (you are better offer buying flanges from one of the cadillac forum vendors), cutting off the collectors and repiping the headers for my car.

[455HOGT37]

The Chevy headers are not a bolt up, but once the Chevy flanges are cut off and replaced with the vendor supplied adapters, they fit the Cad head. There is some tweaking required, but it is not always a complete rebuild of the header. Also, the geared starter is easy... Small block Chevy with the dual polt pattern and "clockable" body works just great. Been running one on my stock '70 Deville for some time with zero problems.

[YVEYANT]

From what it sounds like, your money might be better spent in a Pontiac motor. With all the time and money you are going to spend making that motor work, you could invest in a nice Pontiac motor and put that money into making a stump puller out of it. I thought of the swap before and was told by many engine builders that the Cadillac crank shaft is very thin and does not hold up. Supposedly it was notorious for being a weak point of the motor.

[JB 472]

The best way to sum up my approach to building my car is to say that I am playing the cards I was dealt.

My first Cadillac 472 cost $100. My second one was free. Throw in one BOP TH-400, two Chevy TH-400's, and an empty Chevy TH-400 case for another $100. Also, a free Dana 60 rearend and suddenly I have the makings of a stout bracket racer. That's right, two engines, three transmissions, and an unbreakable rear axle assembly for $200.

I have been collecting parts for over three years and have yet to come accross a big Pontiac motor. I do, though, have a 215 cu. in. 6-cylinder if anybody wants it.

The Cadillacs are out there. The majority of people I know are looking for the 500 cubic inch version and as such, the 472 often times gets thrown into the deal for free.

There are performance parts for the Cadillac today that allow for a cost effective budget build. For my application, bracket racing, it is not how fast you go but how consistently you do it.

Sure, I have to modify my family heirloom to fit the engine, but I came to terms with that when I stripped the car to see how bad the corrosion was. Of the fourteen body mounts, seven were air gaps and i became pretty disgusted with GM's design approach. It is obvious to me that GM never intended these things to be family heirlooms, so fixing it and making it my own design suits me just fine.

The "daring to be different" thing suits me OK.

[raj]

Originally Posted by big_gto

A stock `70 500 makes 400 hp & 550 lbs-ft of torque.

Those are pre-72 ratings; not the most reliable. Still, those engines are great for the street.

[codyyy]

My teacher had a Caddy 472 engine in his back when he raced his GTOs, it was really fast. He built that particular GTO he said with the flip frame, built up the engine quite a bit. He said he ended up selling the car to a kid back in the day, not even a month later he got a call saying the kid wrapped the GTO around a telephone pole drag racing Woodward and died.
I'd like to run a Caddy engine in a '66 GTO actually, a 500 if I could, but haven't looked into a mild build. I really don't need a huge amount as I don't plan on hardcore racing.

[69LeMans350]

I see the Caddy forum link was already posted, lots of info there for a swap.
Check out this link as well:
http://cad500parts.com/

[455z4ever]

I have a 500 cad in my 85 chevy 4x4 plow truck. with 3.08's and 31" tires it cruises at 2200 at 60mph.. If you wanna do it, you won't be sorry.. The 75 50 I have is listed at 400 ft.lbs at like 2000 rpm.. When I crack the secondaries in a 5000 pound 4x4 at 60mph it sets you back in the seat. Torque rules!! Don't go any higher then 3.23's and you'll be VERY happy! The big caddy prefers to lug against a high gear ratio.. A friend put a built 500 caddy in a malibu and overgeared it with 3.42's.. Didn't feel much better then a built small block.. He later put it in a truck with 3.08's and it scared the crap outta him!

[455Grandville]

Keep in mind those 500 Caddys dont like anything over 4500 rpms - the rods and valvetrain may not survive.

[cooke]

IMO the biggest hold-back to the CAD swap is lack of 'bolt-in" hedders and the rocker-arms when used in severe duty applications. The motor mount issue is really not a big deal. Pretty straightforward. Set the motor in and keep moving it around until you like where it sits and weld your 'plates' to the cross member and go from there.
The Eldorado pan and pick-up tube is what is required to do the swap on most rear sumped GM cars (A & G bodies).
They are torque monsters and it's pretty easy to go fast with few aftermarket pieces. There are several 12-11 second drivers out there using mild 3.08 geared set-ups. The first Hot Rod Magazine "Pump-Gas" drags hosted an LX mid 80's mustang that used cast pistons, stock rockers, etc and went low 10's on spray and a few months afterwards went some 9.90's.
I personally went 10.50's all motor in my Lemans with a flat-tappet camshaft, TH400, 3.73's, 9" tires through the mufflers. There is limited aftermarket support; so you'll have to be patient if you start getting exotic.
They are about 25lbs lighter than a BBC, offer 5" bore spacing and with a head change you can go from a mild 8.5:1 CR to a stouter 12:1 CR depending on what year model heads you choose. The 472 cylinder heads are the ones I used and they flowed 242 cfm stock. 330 cfm is obtainable with bigger valves and porting.
It is by far easier to go Pontiac and go "bolt-in" all the way. But if you've got some patience and want to be different; then they are definetly an alternative engine that offers big torque at a low rpm which makes for tighter converters and interstate friendly gearing.
Hope this helps.

[speedshopmike]

one of my regular customers has a 500 in his 67 le mans.
looks like it belongs there, including the goofy central mounted a/c.
a former employee is his close friend and helped him with the swap.
he's got a 200r4 behind it!
it hurts the back tires so bad it's not even funny.