Hey y'all.

I just joined the forum, and I'm looking to learn from y'all as I contemplate pulling the Olds 307 from an '88 Cadillac Brougham and dropping in an Olds 455 or 425...I'll post in the correct area after I look at what's already been discussed on this topic...

Warm regards,

Russ

 

Welcome Russ. Nice looking Caddy, that would be a powerful cruiser with a Big Block Olds, for sure!

 

Thank you, Greg!

 

Welcome Russ. I have a dark blue one just like it. Still sports the 307...

 

thanks, Mike!

 

Welcome from the eastern shore. Where about are you. Nice looking car.

 

Thanks, Larry. I'm in Upper Marlboro.

 

Welcome Russ
Nice car looks super clean
I am in Rockville
I have a complete 66 425 with B heads stock bore stock manifold if you decide to go 425 let me know
need the room 400.00
Pat

 

Thanks, Pat! I may be getting back to you on that 425. I posted in the engine forum (under small blocks) looking for opinions...waiting to see what folks think.

 

Welcome to the group... IMO, the big block is the way to go... Much more power with minimal work then the small block...

 

Thank you, John! I appreciate the input!

 

The 425 was the engine that was installed in the 77-79 Cadillacs I believe.

 

Thanks, Bfg! I think the 425 Cadillac used in '77 was a Cadillac motor, based on the 472...

See https://bangshift.com/bangshift1320/...-and-cadillac/

 

Welcome Russ, beautiful car through and through.

Full size 4200 LB car should have a full size engine. So I am with the go big block sentiment. Yes as you mentioned the late 70s 425 is Cadillac and not really worth the swap in my opinion. Its just a diluted 500... Olds 425 on the other hand is as strong as an Olds engine got and is the direct predecessor to the legendary Olds 455. You will of course need to upgrade the Cadillac's drive-train. I'm not sure what trans and rear you have but if its G-Body like that could be an issue ?

P.S. if you want to see your car in all its splendor watch The Color of Money 1986 starring Paul Newman. He drives a gorgeous version, filmed and revered as Cadillac surely intended it to be perceived. Wealth, class, and luxury.

 

Thank you, Phil! I'll definitely check out that movie, and I'll pay attention to ensuring the drivetrain can handle whatever is at its front end...

 

My pleasure Rocket, here is a little taste of the Cadillac. 2 minutes of movie immortality, obviously I am not alone when it comes to admiring Broughams. Typed in info on YouTube and it came right up.

Featured from 0-20 seconds and again 1:47 to 2:20


By the way what is your engine code (8th digit of vin number) ? I have heard that some late 80s Broughams came with 442 engines which are code 9...

 

Thanks for the clip! I have the "Y" code...from reading Cadi forums, I think the "9" code motor may have only come in livery service examples (most probably intended as chassis to be converted to limousines), which also had a TH350 instead of the 200/4R that's in my car...

 

That makes sense with regards to the code 9. And so does the TH350 part.

I also have a 1987 numbers matching 442. Rough condition but runs like the wind. The 442 came with the hi performance version of the TH200-4R , great transmission. Its my understanding the later regular versions like whats in your car is also a great trans minus the go fast mods... My gut instinct is go big with a big car so I said big block. But I skimmed your other thread, where you also mentioned possibly going with a 403. And now I also agree with olds 307 and 403. I'm thinking your trans will cope with the 330 LB FT of torque a lot better than a big blocks torque, which could be 400 or more net.

A healthy 403 will be a marked improvement over the stock 307, and you may be able to get away with your stock drive-train as is... Assuming you have an 8.5 rear...

We are talking about a 50 HP boost in power and 80 LB FT in torque. If she couldn't peel out on a dead punch stock. She should with ease with a 403 swap. It should feel like a real kick in the pants when you throttle up.

 

Thanks, Phil. I'm still on the fence re: BBO vs SBO...

There are definitely pros and cons to both that I'm trying to weigh, and really still learning lots of things I hadn't even considered before coming here, so probably plenty more pros and cons I've yet to learn. At the same time, I don't want to overthink, so I'll deliberately pivot to decision making mode after a reasonable brainstorming period.