1970 Cadillac DeVille Convertible 500 ci from North America


Big heavy beautiful, 10mpg-ish


Pretty much everything.

General Comments:

Bought this car all rusted out and have put a tremendous amount of work into it. It's now totally reliable and I'm probably 25k into the project. 8 MPG top/windows down, 10 MPG top/window closed.

Some of the new items over the years:

Window regulators, track guides, all weather striping/felts, cloth top, top motor, top lines, top switch, brake booster, master, lines, calipers, all 4 discs, fuel lines, transmission lines, battery cables, dual exhaust, Sanderson headers, rear axle switched to a 1996 impala SS with police package and positive traction, gearing switched to 4.11 (about 3800rpm at 70), all seals and bearing changed, transmission rebuilt, engine rebuilt hot, 10 to 1 pistons, Lunati voodoo cam, port/polish/over sized stainless valves/triple springs in the heads, high flow water pump, triple pass radiator, remote transmission cooler, high flow thermostat, 200 amp alternator, twin electric 16 inch cooling fans, Flexalite high volume mechanical fan, bottom 12 inches of every panels sheet metal replaced, new radio that fits in the dash, new wheel bearings, new wheels (kept loosing wheel covers and they aren't cheap), all new front end bushings and ball joints, all rubber parts, the list goes on.

I just try to upgrade one system at a time per year and after 10 years it's a fast, reliable, good looking car.

Would you buy another car from this manufacturer? Yes

Review Date: 18th April, 2021

19th Apr 2021, 22:14

Nice review. I'm assuming you swapped the 500 motor in place of the original 472? As the 500 in 1970 was only available in the Eldorado and was used in the DeVille starting in 1974. Easy swap, the engine blocks are identical.

24th Apr 2021, 22:34

I had a 72 Deville, but always liked the look of the 1970 better. Got about 15 mpg (that’s imperial measurement).

1970 Cadillac DeVille 7.7 from North America


Rides nice, well built and reliable


Rust, especially in the lower front fenders.

Seat lock mechanisms not functioning.

Vent runs air when in off (blower motor stays on).

Suspension in the front is loose in areas.

Driver's door won't stay locked.

General Comments:

I like the car, I've always loved the 70s Cadillacs because they were all new when I was a kid, and I remember how impressive they were, and how a guy's Cadillac trunk lid opened up by itself one day out in front of the house... "MAGIC" I thought.

This car was owned for many years by a rancher in central Montana, so most of its miles were driven on gravel country roads. It runs like a dream and still drives very nice, but it will need work, and the inside is very dirty (but improving). I will end up putting a lot of money into the restoration, but when it's done it will bring smiles every time I take it out.

The interior needs re-done, dash needs cleaned up, but it won't be too hard to get it right again.

It's hard to find fenders without all the damn rust though (bad design).

The car is absolutely loaded with all options in 1970 (another reason to fix it back up). Comes with cruise control (not working), which I didn't think was a big deal until I realized that 80% of all the '69 and '70 models I've seen in junk yards or for sale on the Internet do NOT have cruise control. Overall, a nice riding car still, and powerful. Many options.

This car will be a beauty again some day, but for right now, I keep it hidden. Takes a lot of money to get these back, so... till that day.

Would you buy another car from this manufacturer? Yes

Review Date: 19th March, 2015

20th Mar 2015, 12:52

The blower motor running when "off" is not a "fault" -- all GM products in the early '70s were designed that way, supposedly to prevent the buildup of carbon monoxide inside the car.

Try reading your owner's manual, it's a beautiful thing.

22nd Mar 2015, 03:05

Good point about the blower motor running after the ignition is switched off. The thing is, I thought GM started that in 1972-1973. Might be an electrical malfunction.