: 454 question



Phantom0023
11-25-10, 11:31 PM
Hi all! I have been looking around the forum for a few months now looking at all the info that you guys have posted here, i searched for a few hours the other night for an up coming project i would like to take on, but cannot seem to find info about it. i have a 93 Cadillac Fleetwood, the car is in great shape and I am its 2nd owner in its 18 years of life, the car has 178,000 miles on it and runs great, but its starting to show its age. I was wondering if at all possible I could put a 454 under the hood? But I have a few questions about doing it. I have been trying to find the answers to:

1. has it ever been done? at least with this year and model.

2. if i decide to do it should i carburetor or should i find an engine with a throttle body? if i where to throttle body it i assume it would be better to get a donor vehicle. (i would honestly prefer a carburetor fuel mileage is not an issue... )

3. if I where to put a carburetor on it would this have any effect on the digital instrument cluster? I'm expecting nothing more than a check engine light. (sadly one of the things i mainly dislike about the car, aside from the small mirrors)

4. should i worry about frame flexing? this is one of the things I have heard horror stories from a few friends with Camaros' talking about strengthening their frames.

5. clearance, I'm not quite sure about how much of a height difference the 454 will have over the 350, I'm guessing this won't be an issue.

6. what rear end would i use? tranny is not an issue would probably be a TH350, i plan on putting some clutch packs and such in it I'm pretty sure Summit sells kits for them, and maybe another valve body, I love working on transmissions. I also figured a new drive shaft will have to go under her as well.

I also understand that new springs will have to go under the front of the car 70's Chevelle? Also, the engine mounts, but these are easily remedied.
just some questions i have been wondering about, hell i might even just put another 350 in her, just the 454 thing has been nagging at me since the day i got the car.

Hairball
11-26-10, 12:24 AM
There should be NO problems or issues with putting a 454 in a Cadillac Fleetwood (just wonder WHY you would want to). There will be NO issues with hood clearance or frame (the Camaro frame is no comparision to a Caddy frame), shocks, TBI/carb or probably much else.

I just don't quite understand why you would want to make a "hot rod" out of a huge, heavy luxury car but that's your choice.

I didn't know they made many 454's with TBI. Most of the ones I've seen were carbed.

I wouln't worry so much about doing much to a tranny other than a good shift kit and a smaller converter, something in the lines of about a 3,500-4,000 stall speed. A TH350 will only work if you built the heck out of it, otherwise I'd opt for a TH400.

If you still want to make a street machine out of a boat, don't forget to install a posi rear end like a Chevy 12-bolt (9-inch Ford or Mopar Dana-60 would be better, but more expensive and harder to find).

I'd love to see pictures of this project when you start. You're going to find it a lot more work/mods than it's worth.

But hey, a buddy of mine who builds race cars and narrows rear ends put a narrowed 9-inch Nodular Case Ford rearend in a heavier Caddy than yours and turned it into an all-out race car for a customer! It only turned 12's, even though the customer tried a 600 Holley, then an 850 Holley double-pumper, then a Predator, then a blower. No matter what he tried for induction, he couldn't get lower than 12's. This is the car when the rearend was being narrowed and getting ready to be installed...
http://i254.photobucket.com/albums/hh100/Hairball98498/SOME%20car%20pics/136-6.jpg
http://i254.photobucket.com/albums/hh100/Hairball98498/SOME%20car%20pics/136-5.jpg

Good luck, man! Sounds kind of cool!

sven914
11-26-10, 01:31 AM
The lest gen Fleetwoods used pretty much the same frame setup as the earlier '80's and late '70's Cadillac RWD's so strength is no issue. For the engine, I would say use a carburetor because you need to install a different computer to govern the fuel flow of the 454. You need to look through the computer control system of the vehicle, to see what systems will be effected by a different engine or a disabled computer, but on '92 and earlier vehicles, you can just disconnect the computer and the car functions normally without it.

My only question is, why do all this work to swap a Chevrolet for an Oldsmobile? You already plan on dropping to a three-speed behind a carburettor, so why not strive for an authentic Cadillac engine? I'm not certain about the exact changes made to the last gen chassis, but on the '92 and earlier RWD's, the 368, 425, 472, and 500 Cadillac engines are direct bolt ins, and you don't have to hassle with fabricating mounts and recontouring the frame to fit the engine.

csbuckn
11-27-10, 01:34 AM
1. has it ever been done? at least with this year and model.
I dont think anyone here has done it


2. if i decide to do it should i carburetor or should i find an engine with a throttle body? if i where to throttle body it i assume it would be better to get a donor vehicle. (i would honestly prefer a carburetor fuel mileage is not an issue...)
Go carbed if you put a big cam in, go TBI if your cam is close to stock. You can take the computer out of the same truck that the 454 TBI motor comes from or get a custom chip burned.

.
3. if I where to put a carburetor on it would this have any effect on the digital instrument cluster? I'm expecting nothing more than a check engine light. (sadly one of the things i mainly dislike about the car, aside from the small mirrors).
The tranny will give you problems with the digital cluster. If you take out the 700R4, you will have to find a way to make the digital speedo work. A th400/350 will probably have a cable driven speedo cable instead of the electric one you have now.


4. should i worry about frame flexing? this is one of the things I have heard horror stories from a few friends with Camaros' talking about strengthening their frames.
IDK my BFF Jill. Probably wont have any issues


5. clearance, I'm not quite sure about how much of a height difference the 454 will have over the 350, I'm guessing this won't be an issue..
No problem


6. what rear end would i use? tranny is not an issue would probably be a TH350, i plan on putting some clutch packs and such in it I'm pretty sure Summit sells kits for them, and maybe another valve body, I love working on transmissions. I also figured a new drive shaft will have to go under her as well..
Just keep the rear end that you have now, it'll do well with no overdrive.


I also understand that new springs will have to go under the front of the car 70's Chevelle?
Go with shocks and springs for a caprice, they go right in and should help with controlling the big car.


Also, the engine mounts, but these are easily remedied.
Going from a small block chevy to a big block chevy shouldn't need new mounts but I'm not 100 on that.


hell i might even just put another 350 in her, just the 454 thing has been nagging at me since the day i got the car.
Might as well do the 454. If your lucky, you can find a 454/th400 out of an early 90s work truck/van that had the digital cluster. That would be golden.

Phantom0023
11-27-10, 03:59 AM
Thanks for the info, now I am gonna have to total up the price of everything and do some calling around, not to mention clean out the garage. this put a lot of questions of mine to rest thanks again! (If i do decide to go along with this project ill make sure to post pics)

cadillac_al
11-27-10, 07:35 AM
There should be NO problems or issues with putting a 454 in a Cadillac Fleetwood (just wonder WHY you would want to). There will be NO issues with hood clearance or frame (the Camaro frame is no comparision to a Caddy frame), shocks, TBI/carb or probably much else.

I just don't quite understand why you would want to make a "hot rod" out of a huge, heavy luxury car but that's your choice.

I didn't know they made many 454's with TBI. Most of the ones I've seen were carbed.

I wouln't worry so much about doing much to a tranny other than a good shift kit and a smaller converter, something in the lines of about a 3,500-4,000 stall speed. A TH350 will only work if you built the heck out of it, otherwise I'd opt for a TH400.

If you still want to make a street machine out of a boat, don't forget to install a posi rear end like a Chevy 12-bolt (9-inch Ford or Mopar Dana-60 would be better, but more expensive and harder to find).

I'd love to see pictures of this project when you start. You're going to find it a lot more work/mods than it's worth.

But hey, a buddy of mine who builds race cars and narrows rear ends put a narrowed 9-inch Nodular Case Ford rearend in a heavier Caddy than yours and turned it into an all-out race car for a customer! It only turned 12's, even though the customer tried a 600 Holley, then an 850 Holley double-pumper, then a Predator, then a blower. No matter what he tried for induction, he couldn't get lower than 12's. This is the car when the rearend was being narrowed and getting ready to be installed...
http://i254.photobucket.com/albums/hh100/Hairball98498/SOME%20car%20pics/136-6.jpg
http://i254.photobucket.com/albums/hh100/Hairball98498/SOME%20car%20pics/136-5.jpg

Good luck, man! Sounds kind of cool!

That's my Seville!! At least a look alike of when i bought it. They make good hot rod material but they are a little heavy for drag racing. I saw a black one once with a 454. I was supposed to take mine to the strip this summer but didn't make it.

http://i491.photobucket.com/albums/rr276/cadillac_al/th_2010393.jpg (http://s491.photobucket.com/albums/rr276/cadillac_al/?action=view&current=2010393.jpg)

http://i491.photobucket.com/albums/rr276/cadillac_al/th_2010398.jpg (http://s491.photobucket.com/albums/rr276/cadillac_al/?action=view&current=2010398.jpg)

A properly built 454 would be nice in a Fleetwood but not a FI transplant form a truck; those things were dogs.

sven914
11-27-10, 07:46 PM
My only question is, why do all this work to swap a Chevrolet for an Oldsmobile?

I got my displacements mixed; thought you were talking about the Olds 455.

N0DIH
11-29-10, 02:57 AM
The presidential limo had a L29 454 in it from the truck line, appropriately modded of course....

el_chupacabra_99
12-09-10, 12:44 AM
...
My only question is, why do all this work to swap a Chevrolet for an Oldsmobile? You already plan on dropping to a three-speed behind a carburettor, so why not strive for an authentic Cadillac engine? I'm not certain about the exact changes made to the last gen chassis, but on the '92 and earlier RWD's, the 368, 425, 472, and 500 Cadillac engines are direct bolt ins, and you don't have to hassle with fabricating mounts and recontouring the frame to fit the engine.

^^This^^
Especially if you may go with a carb...keep it all Caddy. Find a 500 and go big.