Teach Me About Giant 60s Cadillacs

In reply to yupididit :

IIRC look up CaddyCarlo?  I think he was the one that did a lot of manuals behind the 472/500s.  I remember something about drilling the crank for a pilot bearing.

In reply to Stampie (FS) :

Looks like a 4L80 or 6L80 will have to do lol

In reply to yupididit :

I'll send you my Dewalt drill if you want.

Of all the tail fin caddy of the 50s and 60s - that are gorgeous - which is the most reliable of DD? 

In reply to mr2s2000elise :

Wow gorgeous vs. reliable but no mention of cost.  I'm going to say 57 Seville.  The gorgeousness is so high it doesn't matter how reliable it is nor the cost.

yupididit said:

maschinenbau (I live here) said:

yupididit said:

Stampie (FS) said:

In reply to Appleseed :

He also swapped a big block Cadillac motor in it.

Hmmm!

I have to wonder, in a racing application, if a larger, European engine with more cylinders would be better

 

I just wonder how a cadi 472/500 with a t56 behind it would fit in a certain car lol

It would fit until the first time you mashed the pedal and the T56 ejected the main shaft into the clutch and blew off the tailshaft.  Then it wouldn't fit very well.

Stampie (FS) said:

In reply to mr2s2000elise :

Wow gorgeous vs. reliable but no mention of cost.  I'm going to say 57 Seville.  The gorgeousness is so high it doesn't matter how reliable it is nor the cost.

That is stunning ! 

OHY!!!!

How about a '77 DeVille?  This one is super close by.

that will be peak emissions era would it not? so like 180hp from a 500ci engine

In reply to ¯\_(ツ)_/¯ :

That'll have a 425 so the smaller version of the 472/500.  Same stroke as the 472 but smaller bore.  Still not a bad engine with some tuning.  It'll have the th400 trans so that's bulletproof.  

MrChaos said:

that will be peak emissions era would it not? so like 180hp from a 500ci engine

235 I think, but just a few bolt-ons away from 1hp/ci.

The 425 had better heads with smaller chambers.  You can always tell a 425 because it has a cast iron single plane intake.  Odd bird.

Ported 425 heads on a late (low compression) 500 is a sweet recipe.  Gets you decent compression, great flow, and that is the easy button for heads that can potentially do 500hp on a 500ci without selling a kidney to get Bulldog castings.

In the past, Maximum Torque Specialties and Cad500 were the two go-tos for Caddy performance.  I think MTS bought C500.  They publish their own book on Caddy performance that is really good.  I might have one or two.  I remember going through some books recently and I may have sold/donated/trashed them, but a worthy read.

#1 thing to do if you're upping the oomph on any of the Caddys... rail mounted rockers.  Factory rockers are on a T-bar with little retainer clips.  If the clips don't fail, the T-bar breaks.  They'll last forever with factory lifts and springs, but upgrades put a hurting on them.

In reply to Curtis73 (Forum Supporter) :

I can appreciate the hot rodding potential, but do you think it needs more power for my intended use?  I want to pull consecutive 1000mi+ days in comfort, if it can maintain 80+ mph happily then that's all I need for power output.

There is one on BAT that is pretty 

but the condition is so so on close up pics

In reply to Curtis73 (Forum Supporter) :

Marty of MTS passed a few years ago and it is no more.

In reply to ¯\_(ツ)_/¯ :

It’ll do that and more. They never were designed for HP. They have torque for days.

You don't have to hot rod it, I was simply mentioning it in case you wanted to up the ante later.  It's just that some of them are good candidates and others have a little more work involved.

Driving a monster-cube caddy is a blissful thing.  A Caddy 472/500 makes so much torque down low in the RPMs that many of them came with 2.37 gears, and I think there was even a 2.21 option.  One of the drag racing tricks some of the entry-level guys would do is pair a stock Caddy 500 with a 2-speed powerglide and 3.08 gears.  Such mountains of torque at such low RPMs, that was a good recipe for getting down the track really fast.

So you can almost completely ignore the HP rating because even in stock, wheezer form they made nearly 400 lb-ft of the stuff at 2000 rpms.  Drive it stock and you won't be disappointed.  Where things get hazy on the cadillac was after the 472/500 came the 425 (basically a smaller bore 472) which was still good, but a bit mismatched, and then we get into the 368 in 1980, TBI, and displacement-on-demand which were nightmares for Cadillac.  They only lasted a few years until Caddy started pulling engines off the GM shelf, like the Olds 307.  I think the 368's last year was 83 in regular cars and 84 in hearse/commercial bodies.  You know the 368 was bad when the Olds 307 was considered a better option.

Generally, here is my opinion:  If you want to just drive it, any of them from the 60s to late 70s will be serviceable, fun, and super stylin.  If engines are important, then here is what I would recommend:

Up to early 60s: 390.  Fantastic engine until something breaks, which is unlikely.  Parts are getting hard to find and expensive.  Not much in common with other GMs, so if you need a transmission, it's not like you can just bolt on something.

mid 60s 429:  Very good engine, began filtering in the BOP bellhousing pattern, parts pretty available

68-69 472/500:  Excellent engines, but the 10.5:1 compression means retarding the timing and running 93 octane.  Parts cheap.

70-76 472/500: Hallelujah, sweet spot.  Monster torque, better MPG, 87 octane all day, parts are cheap.

77-80 425: Similar achitecture to its predecessor, and a fine engine, but a big drop in torque... like dropping more torque than a Miata makes.  

80-84 368:  I wouldn't own one if it was free.

Within those years were some smatterings of Olds 350s, but usually on the smaller Caddys.  After the 368, most Caddys got the 307 up through 1989.  1990-91 were kind of dark years of only FWD until they re-skinned a Caprice in 92 and called it a Fleetwood with an LT1.

I will also say this... having owned an 89 Fleetwood with the 307, it was painfully slow, but it got 19 mpg on the highway and was a great caddy experience.  My sweet spot is either a 62 DeVille for the style and put up with the 390's uniqueness, or a 73 DeVille for the best engine GM ever made and take a tiny hit to my swagger.  Ultimate would be a 62 with a 500 swap, but it's not a simple bolt-in.

If I had your goals of chewing up highway miles, I would (personally) look for a 73-76 DeVille, convert the A/C over to R134, and drive it forever.  that will get you GM parts-bin brakes, transmissions, suspension, alternators, etc that you can find easily when you're 1500 miles from home and get a hotel room for the night while they get the parts from O'reillys.  In the 62, you would likely be stranded for a while while they ordered parts from RockAuto or Amazon.  It will also let you sip 87 octane and you'll be surprised at the MPG you'll get with a good tune-up.  My 500 that I stuffed in a 66 Bonneville got 18 with a TH400/GVOD and 3.73s if I kept my foot out of it.... which was never.... and it was modded with a smaller cam.

In reply to Curtis73 (Forum Supporter) :

Thanks!  Seriously, the year by year summary and the "here's what I'd buy for that" are super useful.   I'll probably drive that '77 since it's like 10min away and look around for deals on cars from a few years earlier.

70 would still be high compression.  Then it started getting lower but I wouldn't consider them 87 octane until the large chamber heads came out in 75.

Stampie (FS) said:

70 would still be high compression.  Then it started getting lower but I wouldn't consider them 87 octane until the large chamber heads came out in 75.

Good catch.  Can't even claim I did a typo because 0 and 1 are on opposite ends of the keyboard.

I wouldn't worry too much about 87 octane on the 71-73 heads.  They were a dished piston to get the 8.5:1 with 76cc chambers, then in 74 they started doing the 120cc head with flat tops.  While it seems like the dishes would kill octane tolerance, it doesn't seem to in the real world.  There are plenty of 71-73 500s out there that sip 87.

From Cad500parts.com:

¯\_(ツ)_/¯ said:

In reply to Curtis73 (Forum Supporter) :

I can appreciate the hot rodding potential, but do you think it needs more power for my intended use?  I want to pull consecutive 1000mi+ days in comfort, if it can maintain 80+ mph happily then that's all I need for power output.

That is exactly what the stock powertrain was engineered for.  Any of them.  Even the 425, because the 425s were only put in the downsized models, so it actually feels like more engine than a 500 in an Eldorado or a 472 in a DeVille.  LOTS less mass after '76.

Added bonus on the 425 is a light weight crank vs the same stroke 472 one.  Less rotating mass.  472s with 425 cranks used to be called street sweepers.

I think the 472/500 is the perfect swap candidate for contemporary GM trucks.  I've often fantasized about a '72 or so Chev/GMC half ton with the big Cad.  

Curtis73 (Forum Supporter) said:

You don't have to hot rod it, I was simply mentioning it in case you wanted to up the ante later.  It's just that some of them are good candidates and others have a little more work involved.

Driving a monster-cube caddy is a blissful thing.  A Caddy 472/500 makes so much torque down low in the RPMs that many of them came with 2.37 gears, and I think there was even a 2.21 option.  One of the drag racing tricks some of the entry-level guys would do is pair a stock Caddy 500 with a 2-speed powerglide and 3.08 gears.  Such mountains of torque at such low RPMs, that was a good recipe for getting down the track really fast.

So you can almost completely ignore the HP rating because even in stock, wheezer form they made nearly 400 lb-ft of the stuff at 2000 rpms.  Drive it stock and you won't be disappointed.  Where things get hazy on the cadillac was after the 472/500 came the 425 (basically a smaller bore 472) which was still good, but a bit mismatched, and then we get into the 368 in 1980, TBI, and displacement-on-demand which were nightmares for Cadillac.  They only lasted a few years until Caddy started pulling engines off the GM shelf, like the Olds 307.  I think the 368's last year was 83 in regular cars and 84 in hearse/commercial bodies.  You know the 368 was bad when the Olds 307 was considered a better option.

Generally, here is my opinion:  If you want to just drive it, any of them from the 60s to late 70s will be serviceable, fun, and super stylin.  If engines are important, then here is what I would recommend:

Up to early 60s: 390.  Fantastic engine until something breaks, which is unlikely.  Parts are getting hard to find and expensive.  Not much in common with other GMs, so if you need a transmission, it's not like you can just bolt on something.

mid 60s 429:  Very good engine, began filtering in the BOP bellhousing pattern, parts pretty available

68-69 472/500:  Excellent engines, but the 10.5:1 compression means retarding the timing and running 93 octane.  Parts cheap.

70-76 472/500: Hallelujah, sweet spot.  Monster torque, better MPG, 87 octane all day, parts are cheap.

77-80 425: Similar achitecture to its predecessor, and a fine engine, but a big drop in torque... like dropping more torque than a Miata makes.  

80-84 368:  I wouldn't own one if it was free.

Within those years were some smatterings of Olds 350s, but usually on the smaller Caddys.  After the 368, most Caddys got the 307 up through 1989.  1990-91 were kind of dark years of only FWD until they re-skinned a Caprice in 92 and called it a Fleetwood with an LT1.

I will also say this... having owned an 89 Fleetwood with the 307, it was painfully slow, but it got 19 mpg on the highway and was a great caddy experience.  My sweet spot is either a 62 DeVille for the style and put up with the 390's uniqueness, or a 73 DeVille for the best engine GM ever made and take a tiny hit to my swagger.  Ultimate would be a 62 with a 500 swap, but it's not a simple bolt-in.

If I had your goals of chewing up highway miles, I would (personally) look for a 73-76 DeVille, convert the A/C over to R134, and drive it forever.  that will get you GM parts-bin brakes, transmissions, suspension, alternators, etc that you can find easily when you're 1500 miles from home and get a hotel room for the night while they get the parts from O'reillys.  In the 62, you would likely be stranded for a while while they ordered parts from RockAuto or Amazon.  It will also let you sip 87 octane and you'll be surprised at the MPG you'll get with a good tune-up.  My 500 that I stuffed in a 66 Bonneville got 18 with a TH400/GVOD and 3.73s if I kept my foot out of it.... which was never.... and it was modded with a smaller cam.

Great info as always Curtis.  Just one minor minor correction to make: there was no 500 in '68 or '69.  It made its debut in "the gilded one" for 1970 rated at 400 hp and 550 torques (gross).