Will Eldorado 500cid engines fit in RWD Fleetwoods?

[My_favorite_Brougham]

I'm not too familiar with the seventies Cadillac engines that were front-wheel-drive, but since an early 70's Eldorado was not a transaxel, can the engine fit in a big Fleetwood Brougham? I'd like to put a 500 in my '90, but am I limited to other Devilles and Fleetwoods? Maybe the engine would fit, and I could get another tranny? Hmm?

[eldorado99]

Both RWD and FWD 500s and 472s (and 425s) were all the exact same, and should be completely interchangeable.

[534BC]

Only difference I remember is in which hole the dip-stick uses, and the pan/oilpump pickup.

[eldorado99]

Oh yeah, the oil pan could be different now that I think about it, not sure on that though.

[90Brougham350]

What about the exhaust manifolds?

[kevin666]

Actually, all of the Eldo's in the 70's were fwd/transaxle...

[davesdeville]

To put a 500 in your 90, IIRC you'd need a mid sump pan and matching pickup. If you get an Eldo motor with the rear sump, sell it for $120, buy a mid sump for $40. I don't know about the accessory drive on a 90 but a junkyard 77-81 will have the accessories/pullies you need if you find you need to change setups.

[My_favorite_Brougham]

Well, I do have access to an '81 Fleetwood Brougham. Could I harvest it for the parts for my '90? Also will the '81's 3-speed hook up to the 500? Or can I use the tranny on my 307? Or can I use the eldorado's tranny?

[BluEyes]

The Eldorado's transaxle is FWD only, leave it.

If the '81 Fleetwood is a 368ci, you'll need the oil pan and oil pump pickup (to match the pan) and the exhaust manifolds.
Actually, bnefore you go swapping oil pans, see where your crossmember is! If your current engine has a rear sump, then chances are that you will NEED the Eldorado oil pan/pickup, NOT the one from a RWD Cad. RWD Caddies had a front sump, but many later GM's used a rear sump. (thus why the rear sump pan costs more - more demand)

The 307 is the Olds motor? If so its trans would have the right bolt pattern, but is too weak in stock form to handle a 500ci long term. If the trans is a 200-R4, then look into building it up if you have the budget. Thanks to the turbo Buick guys those trannies have alot of hard parts made for them and can be built for the job.

You can also get a TH400 from a '70's RWD Caddy but that would lack overdrive.

I notice you plan to keep it carb'd - do you have a smog test in your area? If so that will not fly.

[My_favorite_Brougham]

But are you sure the Eldorado is a transaxel? The engine is not sideways. I looked under the hood and the block is parallel to the chassis just like any RWD car, but the transmission is just different to make it FWD. It wraps around under the block from what I could see. And I have seen other 80s Fleetwoods with 500cid engines from Eldorados; this guy did it:

1981 Fleetwood with an Eldorado's 500

Anyway, what's the trouble with keeping it carburated? I think I can just put a some emissions fluid in the gas just before inspection. Besides, can an engine be converted to fuel injection? - feasibly?

[kevin666]

The way an engine sits does not mean it has a transaxle or not. It all has to do with the way the transmission transfers the power to the wheels. My 1975 Eldo engine sits front-to-back but it is still is front wheel drive and has a transaxle.

[My_favorite_Brougham]

So transaxel refers to the transmission, right? That would mean that the block, however, is still like the RWD machines, right? After all, I would hook up a different transmission.

[davesdeville]

Transaxle is a combination of the words transmission and axle... it serves as both the transmission and the differential/axle. All 500/472/425/368s will fit where any 500/472/425/368 was before, no matter what car (there are minor exceptions like exhaust manifolds or valvecovers that aren't anything to worry about.)

[Ted in Olympia]

If you want to put a 500 from an Eldorado in to a Deville/Fleetwood that came with a 472 or 500, ie 68 to 76 or a little later with a 425. It is a direct swap. All you have to do is change the oil pan, Driver's side exhaust manifold, starter, and motor mounts.

But putting one in a 90 that I think came with a 307 olds would be a completely different story. This is an engine swap and would be no different than putting a 500 in a Mustang or G-body, you have to design everything as you go.

Even though some 500 came with FI, it would not be easy or cheap to convert one.

TED

[BluEyes]

Originally Posted by My_favorite_Brougham

Anyway, what's the trouble with keeping it carburated? I think I can just put a some emissions fluid in the gas just before inspection. Besides, can an engine be converted to fuel injection? - feasibly?

If your state inspection includes emissions they probably do a visual check for the emissions equipment. That means that you've gotta have all the original stuff that came on *your* car. Pretty sure that includes the EFI system. You might be in for a bit of a scuffle with the 500ci itself. EPA rules only allow an engine to be swapped into a car if the chassis originalls could have had that 'class' of engine. I'm pretty sure that '90 Caddys only came with smallblocks and the 500ci is a big block so "by the book" this is an automatic fail from the get-go. Technically these rules apply to everyone but it really comes down to your local laws. Where I live there is no inspection, so the Government is none the wiser about anything, but in most metropolitan areas they are likely to give you some trouble. You've also got to think: does the inspector even know what engine he is looking at?

Putting EFI on any engine is very feasible. All you need is an ECU, some sensors, injectors and a manifold that mounts the injectors instead of a carb. You've already got most of what you need on your car since it should be EFI. The GM ECU's are pretty throughly hacked so I'd bet that you can re-tune the computer you've got to run the 500.