Hi Gary, Sorry about how long this turned out, but I think you'll find it's a worthwhile read. The Cad 500 into '73 LeSabre was not totally stratightforward, but nothing unexpected happened either. Cad Company as they used to be called, or now FlashCraft, is a great resource. They offer adapter frame pads and header flanges. You need to find an Eldorado (FWD) oil pan and pickup tube for the oil pan to clear the frame. For headers, you buy BBC(hevy) big car headers and cut the flanges off as close as you can to the welds, then a little massaging and the header tubes can be welded into the new flanges. I recommend having your welding guy affirm that he can do this before you get started. I will say that I was very nervous before we tried the header thing, but once we got into it, it turned out to fit really well and was pretty smooth. I went with the cheapest BBC headers I could find (in case we screwed it up) and then repainted them well after the welding was finished. Expect to put the motor in and out a few times throughout the process... I didn't have any other physical fitment issues to speak of. The heater hose coming out the back of the passenger side head, I had to put a 90 elbow there but it was no big deal. Nothing else had any clearance problems that I can recall. Keep in mind I built this about 20 years ago and pulled it apart about 10 years ago. The A/C lines were not long enough, and cad used fittings that were opposite the Buick, so I had somebody affix (tig welded I think, it was a long time ago) the cad aluminum A/C lines to the Buick aluminum on the back of the A/C pump to get it working. I found that my cad motor always always ran very hot. I eventually stopped worrying about it after I figured out that they just run hot, and it's expected. A 160 tstat won't stop it from running hot. Make sure your cooling system is up to snuff, run at minimum a 15 lb cap (18 would be nice) and don't worry about the 210 + temps you will regularly see. Maybe my motor had some kind of blockage in the cooling system. After the LeSabre, I took the 500 and dropped it into my '86 Suburban. Also not a cakewalk, but easier to install there than the LeSabre. Didn't have to change anything on the motor to make it work. If you are interested in a motor, I kept the 500 after my Suburban rotted away (the body had well over 350K miles on it). It's been in my garage for about 5 years now, but ran awesome when I pulled it out. It has a cad company street/strip cam, ARP rod bolts, modified rocker arm shafts (they are buick 455- style rocker shafts from flashcraft), the appropriate valvesprings, and otherwise is pretty stock. I still have my '73 LeSabre, and am in the process of returning it to 455-powered after 10 years of sitting with no motor. After reading this entire thread full of opinions on the matter, it's worth throwing my 2 cents of advice in here - after doing it all to the LeSabre and making it work, and driving it for 10 years, I'd look for a nice early 70's Sedan De Ville to build up the motor in if you want to play with the massive cad torque. That cad motor rips like holy hell with just a mild cam, properly built carb and some headers thrown in for good measure. For all the physical efforts it took, I think it would be easier to build a good 455 for the LeSabre, and build a good 500 for a Sedan De Ville. The chassis stuff just goes so much easier in the big caddy, and that's where the motor was designed to sit. My LeSabre originally had a 350, and I came across the 500" and it was what I had, so I went with it back then. I'm glad I did it, but if I were to do it all again (and I am), I'd do a nicely built 455, which can also roast tires like crazy and scream like mad, only is easier to install!
Thanks for that great post. .. appreciate all the details. curious what kind of mileage you got with the 500? Ive been reading its benefit is it makes so much torque at low rpm and is much more fuel efficient, talk of 23mpg with 500 inches and globs of effortless torque. thats what got me initerested to begin with. appreciated Gary
I did not have a good setup in my LeSabre, 3.42 gears, which was a mistake. In my suburban, I went from 10-12 mpg with the 350 chevy to 16 mpg with the 455 to 10-12 with the 500. However, my driving habits changed - after installing the 500 I did not use the 'burb so much, and did more city-type driving. I think 10 mpg in city driving with 500" is pretty darn good. I spent a lot of time getting the carb and timing working right. The 455 and 500 both pulled very very well (I did a lot of towing).
Humm, I have a 72 Eldorado out back that has a 500 with only 65K original miles on it and it runs like new. The car is in excellent shape both mechanically and body wise with no rust, excellent white leather interior, I just haven't decided what I want to do with it yet. o No:
Thank you for posting that one. I have waiting for a call about 500 engine. He call yesterday, and say i can pic up engine this weekend. I am going to put it in my Electra. Goran
one of the cheapest hp you can get, simple comp cam , high intake alum, mild head work, electric fans, and custom duals are making 600hp and 750tq at rear tires. The top end is good too similar to Chev big block. Cadillac performance has heads, cams, intakes, rods, double groove bearings, harden rods , lifters, etc. Small buicks may not take well to wide motor compared to 430/455. One problem is same as Buick is the oiling of front filter and pump. Oil galley drill should be done. best is 68-70 472 375hp, or 500 at 400hp factory numbers. Had my '68 caddy, spin tires so hard could not see car except front clip, Evenually had to replace motor mounts. Big Quads are on top of the caddys, bigger than Buick or Olds, big blocks. Dont agree with a Caddy in a Buick, but good motors, and long forgotten till late customizers of Caddys and rods. Pondered a 500cu in a Vega one time, go cart with motor.
I'd be drag racing a '75 Sedan De Ville with a 500CI Caddy if it didn't get totaled back in the late 80's. They are full of torque. I used to get the front end to jump off the ground if I hit the gas timed right with the brake. Sure you can put a Caddy engine in a Buick, but why? Why not a Chevy or a Pontiac or Olds engine in a Buick?!? I say keep a Buick engine in a Buick, and the Caddy engine in a Caddy. It's where they belong. It sounds cool because it can be done, but not cool enough for me. :bglasses: Cheap Caddy add on HP parts? Thats a new one on me. Now, about that HT4100 engine Cadillac had.....:shock: http://en.wikipedia.org/wiki/Cadillac_V8_engine#HT-4100 Meanwhile, enjoy this Chevy powered Caddy. http://justanothercadillac.com/ ElectraJim
4100 caddy, boat anchor, the 425 was caddys last good motor. which was a 472 detuned down. The 4100 steel block and alum head, shifted the gasket so bad they all blew gaskets out. and wrecked the cranks. JUNK, Buick worned caddy with the early 231 of 1960 with the sleeve and alum try, they failed, too. I have a Seville bently back, dead here, with 4100. cant find any one to tell me how to re do into a 80 Eldorado 350 olds motor into my Seville and make all work, seams the ECM wont work with it, and the wireharness is only 4100. Wanted to go back to the simple carb and motor 350 onto the transverse eldo tranny. If you have info on the interchange of motors into bently sevilles cars, let me know
82-87 caddy had rotton alum motor problems, in sedan , seville and eldo, most of which are not junked due to motors.
No. I don't think we ever took it down the 1/4 mile, but I think I used an accelerometer which indicated low 15's. Although it had low-end torque that could kill a moose, it didn't rev that high. The cam was also changed at some point which allowed somewhat better breathing, but I don't think this made the difference between a 15-second car and a 13-second car... However the car has been on the scales at 5700 lbs, so 15's isn't all that disappointing. -BC
youre saying that you havea a 1973 Lesabre that was 5700 hundred pounds? Ive seen them range from 4200 to 4700 but 5700? thats 1500lbs different? geez.
That's what the scale showed. I mean even the headlight bezels have to be 50 pounds! There is no question it is a LOT heavier than my A-body, which has tipped the scales at 4200 pounds. -BC
be sure to tell us if that weight includes a full tank and / or driver. i pretty much believe it though. the 71-76 C-bodies are fricking humongous.
