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472 & 500 Cadillac's?

The Griff

High drag, low speed
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Who wants another thread from me? You do!

I sure this has probably been mentioned elsewhere, but here goes nothing.
The anemic little 305 in the Blazer has started to behave like every other 305 out there and smokes on startup now, and I've started milling over the ideas of engine swaps, and the big Caddy's keep coming back to me, they have always been one of my favorite engines, and 15 MPG isn't just a pipe dream with them, as long as you treat it right.

Has anyone on here done such a swap? And if so, what kind of fabbing is needed? I know they have the BOP style bellhousing, so what would be involved with keeping the transfer case? Could I take my tailshaft and put it on a BOP TH400?

This is all just a pipe dream at the moment, but a guy can dream right?
 
I can tell you some how too's,but since this is the lounge,it might not be ok with other members to discuss "tech" here!...
 
Oops, sorry everybody, this does belong in the garage, I don't think there is a way for me to move it, so it looks like a higher power is needed?



So, uh, who all saw the new Walking Dead tonight?
 
I seem to recall Kert @ DIY4X having a Caddy 500 in the old Blazer... might dig around this thread:

http://coloradok5.com/forums/showthread.php?t=253333

-- A


That thread has probably all the info you'll ever need. IMO, the only reason to go for a Caddy 472/500 over a BBC is if you want something unique or different, or happen to have the engine. Most of the conventional Chevy compatibility doesn't apply, you'll need to do some fab work or get conversion parts to make your Chevy parts work with it. Aftermarket support is not near as generous as it is for SBC/BBC. They are neat engines though, and definitely low-end torque monsters.
 
That thread has probably all the info you'll ever need. IMO, the only reason to go for a Caddy 472/500 over a BBC is if you want something unique or different, or happen to have the engine. Most of the conventional Chevy compatibility doesn't apply, you'll need to do some fab work or get conversion parts to make your Chevy parts work with it. Aftermarket support is not near as generous as it is for SBC/BBC. They are neat engines though, and definitely low-end torque monsters.


Yep.

They are an interesting choice if you are keeping them "stock" and can get one cheaply.... if you want to mod them for more power, it's going to cost you more than a more traditional BBC by the time you are done with all the custom stuff.......


-G
 
I came very close to swapping a 500 Caddy into my '79 C-10 after its straight six lost the #6 piston ring lands and scored the cylinder enough for me to consider it un-rebuildable..

I had a '76 Coupe Deville 500 engine sitting in my shed,complete from air cleaner to oil pan,even had the A/C compressor and altenator..and the original TH400 with the super long tailshaft..

I decided it was easier to just put a 305 I had in it from a '86 chevy van instead--but I kind of wish I had gone thru with the caddy swap.

I had bought a engine adapter plate at a swap meet made by Trans-Dapt that allows a Caddy-Buick-Pontiac engine to bolt up to a chevy pattern trans,which would simplify things a lot in a 4x4,but my C-10 being 2wd,could have used the TH400 with a shorter driveshaft...you can swap a 4x4 TH400 tail shaft into the B-O-P Caddy Th400's too...

I read on a website I found on google when I searched for caddy engine swaps named "Chevrollac" that showed how a guy swapped a 500 onto a truck like mine,and it required two pieces of flat stock 1/2" thick to allow the stock Eldorado motor mounts to bolt to the spot the chevy mounts did on the crossmember--that part was the easy one,what made me decide not to use the 500 was the fact I had no money to buy an eldorado oil pan,that had the rear sump...there was none available locally reasonably,and though I heard the 425 pan and the "mid sump" pan on my '76 engine could be made to work,I just decided to go with the 305 instead...

That article stated you had to flatten the "seam" around the tranny hump in the firewall on the drivers side for clearance for the drivers side cylinder head...some other swaps I've seen did not need that done however..

I ended up selling the 500 back to the guy who actually gave it to me 10 years earlier,when he had to move to an apartment--he bought a house with a garage,and offered me 150 for it,so I considered that a storage fee,and decided the thing probably would need a rebuild after sitting that long anyway..

I know of several guys who bought 500's and 472's from the junkyard and put them in chevy pickups,both 2wd and 4x4's,and one guy put one in a '86 Monte Carlo SS,which was a terror on the streets--and a few put them in rat rods and old trucks...one El-Camino that had one was awesome...

I would say the Caddy engines are best left stock,its too expensive to hop them up,and they tend to come apart at high rpms as does most any long stroke engine...if one isn't powerful enough for you in stock form on the street or trail,then I'd say your too hard to please,after riding in and driving a few vehicles that had the Caddy engines swapped in them..
 
Unless you have a ****load of parts already on hand, I don't see it making sense cost wise. You would need a BOP TH400, not sure if it would need the output shaft changed, as I'm not up on the TH400 stuff. Then you need a 32 spline transfer case and adapter for the trans. Not to mention driveshafts.

I say toss a strong 350 in and call it good for now.
 
+2 for style and originality...

- 5 for being as smart or effective as a worked 502, 454, LS, etc...
 
I've heard that 15 - 17 isn't crazy on the highway.

And around 450 ft lbs ins't anything to scoff at either.




I seriously want to get a 500 Caddy, and drop it straight into the Blazer. The most I would ever do to that 500 is maybe a cam.
Supposedly a decent cam can really liven them up.
 
Doing anything like changing the cam,etc,will only decrease mpg,not improve it..sure ,it will gain HP and torque..but at what cost?.....I'd just tweak the Q-jet ,that will gain some power and mileage..

The main reason land barges like late 60's & early 70's Coupe Deville's got 15+ mpg was the fact they were still high compression back then,and they were geared very high,it was very rare to see a Caddy with rear end gearing 3:08's or lower,many had 2:73's or 2:56's...the torque of the big engines made up for the over-gearing...you may have trouble running a pre-70 Caddy on todays ethanol regular 89 octane ..
 
Saw a guy towing a k-30 with 44s into Moab with a early 70s caddy. He had a 500 and a turbo 400. Says he got 14 mpg towing at 65.

It was before the time of camera phones but man he had that thing all set up. Airbags in back and everything. It was awesome
 
I've thought up a dream shopping list/goal for the Blazer as well.

Paint it, Back to its original Midnight Blue.
Limited slip full float 14 in the rear, with an 8 lug 10 in the front.
Either a 4 in or 6 in spring lift.
33 or 35 Bias Super Swampers on White spokes.
Done up with 80's accessories, Old school push bar, Overhead light rack, And a bunch of other stuff I can't remember. (I'm stuck in the 80's, deal with it.)
And with the big Cadillac as the party piece.
 
For New Years 2007, we drove a 1974 Cadilac with a 472 from Lincoln Nebraska to Dallas Texas and back. Got a solid 11 mpg there and back.

1923536_9718851410_3212_n.jpg


Martin
 
Saw a guy towing a k-30 with 44s into Moab with a early 70s caddy. He had a 500 and a turbo 400. Says he got 14 mpg towing at 65.

It was before the time of camera phones but man he had that thing all set up. Airbags in back and everything. It was awesome

I'm sure he got 14 mpg towing ~10K just like my Cummins gets 30 mpg towing a ~10K trailer :haha:
 
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