does anyone have or seen a similar swap?

 

No.. but would be a great swap.. Are you going to do it ?

 

Love the big caddy's and love the LSx platform....hope to get the time to do one of these for myself someday.

 

That would be one smooooth ride. I think I would go the 6.0 route to have a little extra torque to push the big boat around.

Go for it!

Pat

 

I've been kiicking around the idea since I got an extra lq4 laying around. I like the potential of these motors over the existing 472.

 

I'd love to see this swap.

 

man i love lsx motors
but the big ci caddilacs can make some power,and its lighter than a iron block lsx..
let me kno what ur doing with that motor. i can put it in something.. either one of them,,haha

 

Is the 472/500 engine really lighter than an iron block 6.0 LSx? Those are BIG engines!

 

The big caddy engines are torque monsters, which is what you'll need in that big caddy. I would only do the swap if you're gonna be going FI, then I'd run twins...

 

I heard they weigh as much as a sbc

I figured since they put the lq motors in 3/4 trucks and sclade's that they would have no problem motivating that boat.

 

I just sold my cadillac 500, that i was going to add some bolt ons and install in my 79 425 powered coupe deville ; and why did i sell it ??? gotta 2006 lq9 thats goin in, with some bolt ons. looking for 400 rwhp and 20 plus mpg. Sure i could spend maybe the same and make 500 rwhp with that 500 but i'd need a good a4 and FI, Plus i like the wow factor ! build it shouldnt be hard.

 

Listing I saw had the Caddy 472/500 at 625, the BBC at 685 and SBC at 575. So I think the iron block LS motor is going to come in lighter than the big Caddy, but not be enough to make a big difference is a heavy car like that. Like feldZ said, if they can push trucks, Burbs and Escalades around they should do fine with that Caddy and get better fuel mileage, on low octane, than the big Caddy motor.

Pat

 

Stu Cool the last brochure i read from the Cad Company had a 472 - 500 just 40 pounds heavier then a sbc, i meant to mention that in my last post.

 

thats exactly why i was thinking of this swap. I'd drive it to work everyday.

 

exactly, it weighs only 30-40 more punds,, thats the iron intake...
ive read the lsx block weighs more than a bbc block.. dont hold me to it, but ive read it somewhere.. shouldnt matter if ur not racing..
i love both engines.. i now have a turbo 5.3 in my chevelle now, and have thought about going with a turbo cadillac 500 ci..

maybe one day.. good luck on ur build..

 

LQ4/LQ9 weighs about 80 pounds more than LS1. So that makes it about the same as an SBC depending on whether the SBC has aluminum heads and intake. So that is definitely lighter than a BBC.

Pat

 

Having installed a CAD 500 in a 77 Deville and LS3 in a Pontiac GTO clone, I can tell you that the LS3 seems much lighter than the 472/500 and that was with an Edelbrock AL intake on the 500. I had a very difficult time rolling the 500 around and the LS3 was easy. The LS3 was a GM crate engine and the 500 was dressed similar, neither had starters and both had the complete intake system installed. The starter on a 500 is also much heavier than the LS starter. I think the stated weight difference between the SBC and the Cadillac 472/500 assumes that the SBC is all iron, as most SBC now have AL heads and intakes, I don't think the Cadillac is lighter than the typical SBC that is currently being installed by most swappers. Although the Cadillac 472/500 could be made lighter by the installation of aftermarket heads and intakes, however aftermarket heads are very expensive and it is far cheaper to buy a GM crate LS3 than to build a high performance Cadillac 472/500 engine. You can expect to have at least $8000 in the Cadillac engine and that only gets you to about 500HP/600LBS torque. The engine will red-line about 5000 rpm due to the intake restrictions. After market intakes with higher flow won't fit under the hood of almost any street cat.

Although too late now, I wished I had purchased a LS3 for my 77 CoupeDeVille instead of the 500 Cadillac engine. My engine dynoed at 511HP and 600FT/LB but I will be lucky to get 10mpg with this setup, I expect the GTO clone to get close to 30mpg on the highway.

A LSx install in a 68 Cadillac should be easy a swaps go, you have a much bigger engine compartment than the 77-96 Cadillacs and LsX swaps are a bolt in for the 77-96 year range with swap parts available from BRP and Street and Performance. Although not verified there is a good chance that the BRP headers would fit the 68 model. Headers for the 500 from MTS will fit anything from 68 to 96. Given the weight of the 68 I would run a super-charger. My next project is to convert my 68 Eldorado to rear wheel drive and run a super-charged LS3.