not to highjack your thread by any means,but i'm thinking of doing the exact same thing. swap'n out my 331 for a 500.
First released in 1968 as a 472. In 1970, a stroked 500 cid version was released for the eldorado In [about] 1974, the 472 was dis-continued, and the 500 was the only caddy engine offered. Sometime around 1978, it was re-designed as the 425. It's basically the same block, but it got the "pontiac 301" treatment with thinner castings and cost cutting. About the same time, the 368 came out. Again, same block design, but even thinner castings. E.F.I. was first released on the 1973 Eldo 500, and FI remained an option untill the caddy spacific motor was axed in 1984. It uses the same basic components as the 80's model Camaro TPI 305 V8, so there's actually pretty good support for bigger injectors and what not. The Megga-squirt is very popular with the Caddy F.I. crowd. All 472's and RWD 500's use a front sump oil pan and pickup All front wheel drive 500's use a rear sump pan and pickup All 368's and 425's use a mid sump pan and pickup You can not use a front sump pan in anything except a cadillac chassis. The rear sump eldo pan is the choice pan for swaps, but they are rare and $$$$. The mid sump pan will work for about 90% of the swaps. Sometimes slight clearance issues pop up, but it's cheaper to bang a dimple with a hammer than it is to shell out $500 for a good eldo pan. The caddy engine uses an external oil pump that sticks out of the engine at a very bizarre angle. The pump from a 425/368 is much smaller and as such, much more swap friendly. The 368/425 pump will bolt onto a 472/500. The front timing cover on the 368/425 is an improved design over the older 472/500, and it mounts the more modern acessory brackets. Stock caddy intake manifolds are a disaster for a "hot performance" engine. They do flow fine for a granny-mobile, but.... They can be ported to improve flow, but $$$$ to do it. The 368 uses a single plane aluminum intake, while all the others are cast iron dual planes. If you can find a 368 alum intake, grab it up quick!!! While it wont really improve performance, the weight savings are well worth the swap. The edelbrock intake is, however, simply superior. The caddy engine uses the same exhaust port spacing and layout as a BBC. To put headers on one, order for a BBC for your chassis, and cut/weld a flange kit to fit the caddy. There are a couple outfits offering block hugger headers that might work for you also. Evil-bay always has a few sets available. 1974 and up motors all used the HEI. Pre '74 all use standard GM points dizzy. Do not under any circumstances mix-n-match cadillac heads without doing a lot of homework first. Late 425 heads had tiny combustion chambers and small ports. Early 472/500 heads had huge combustion chambers and ok sized ports. Putting late heads on an early motor will give you 13:1 compression and ports too small to feed the engine. Early heads on a late motor gives 6:1 compression. There are no prefered, or "good performance" heads. All early heads flow about the same. All late heads flow about the same... But there is pleanty of meat in the castings to port them to flow very well. Factory caddy cams are extremely mild, and fall flat at ~4000 rpm's. While this is fine for building massive torque, it's not much fun. A cam swap is tops on my list, and the caddy responds very well to an upgraded bump-stick. The valve-train is the #1 performance limiting factor in a caddy motor. The rocker studs are pressed in and can come out if you build power or RPM's. There are kits from MTS and CMD to upgrade the rockers. Because of their "factory de-tuned" nature, caddy's respond VERY WELL to all the traditional hot rod tuning tricks. Caddy cranks are MASSIVELY strong. I dont think I'v ever heard of one breaking, but,,, all caddy's use cast arma-steel connecting rods [like a pontiac]... Fine for under 5000 rpm, but if your going to build power, then forged rods are advisable. Old-school Oldsmobile "425" rods can be made to work, and Ford 460, Olds 403, and BBC 502 pistons can be massaged to fit inside a big caddy... Not for the beginner. The caddy motor was never offered with a manual tranny, but aftermarket suppliers have come to the rescue... Good luck making a saginaw,,, or even a muncie live for very long behind 650 ft/lbs tho. They all used the standard BOP bellhousing. All RWD 425's used a short shaft T-400... Good source for these trannies, but the valve bodies ~suck ass~ as they were designed for low RPM luxo-barges. Get the VB from a Buick 455 equiped car, as they were designed with performance in mind. As stated earlier, the 78-84 caddy "de-ville" chassis is the same as a Chevy Caprice. If you can score the frame pads and motor mounts from one of these, you can practically bolt a big caddy into any GM chassis that had a SBC in it. The Q-jet used on all 425's is actually the "big" 850 model. Tho it's de-tuned for the "caddy ride", it makes an EXCELLENT foundation for a performance Q-jet buildup. The Caddy 500 is extremely light weight for it's CID size. Only about 70 lbs more than a SBC. If you top it with an aluminum intake, it's about the same weight as a mouse motor, so upgrading the suspension for BB weight is not alays nessecary... Tho you will need to upgrade for big power Caddy's produce a tremendous ammount of heat... Dont skimp on the radiator!!! Consider an oil cooler as well as a trans cooler when building one. So........................... Here's tha basic shopping list for a street thumper caddy mill that wont break the bank: *500 cid long block from any 70-77 full sized caddy *Alum intake from a 79-84 Caddy 368 [mostly eldorado's] *78-82 425 equiped DeVille for the: carburetor distributor Radiator oil pump Oil pan with pickup [unless you got the eldo 500] timing cover ~all~ acessories, brackets, pullies, fan and clutch, etc. Transmission [with input yoke] Motor mounts with frame pads *Valve body from a 68-76 Big block buick car Then buy accordingly: *Cam from MTS or CMD. The biggest one that uses the stock valvetrain *valve springs *.030 over stock replacement 10:1 pistons *rings, bearings, gaskets, timing chain *Stock T-400 rebuild kit *T-400 shift kit *1800-2200 stall converter *block hugger headers *Water pump, belts, hoses, etc. Then modify accordingly: *Send the carb to John Osbourne or Jim Wiese *Send the dizzy to GMC BUBBA [30-36* total advance, all in by 2400 R's] *Gasket match intake runners to a depth of 1 1/2 inch. Clean up all casting flash, blend the bowls, smooth the radius around the valve stem area... Dont hog 'em, just clean them up real nice. Blend and radius exhaust side also *clean out all oil passages. De-burr any obvious casting flash, chamfer the mains. *Dont get in over your head if your a newbie!!!!!!!!!!!!! Then assemble accordingly: *Quality machine work with attention to detail *Clean working environment *Set the cam and timing "straight up", or as per your cam suppliers directions *Stock valve job *Pack the oil pump with vasseline [remember, it's external] and rebuild it The above combo is good for an earth twisting 475 hp and 600 ft/lbs, and can be done for under $2400 if you shop around and are capable of doing some of the work yourself.
Lots of great info about the great Caddy 472/500's, the above post pretty well describes the '68 472 in my '36 . I'm using the stock intake as the E manifold won't fit under the hood. The guy who started this thread long ago seems to have decided on a Chev for his S-10 tho...
Is there a certain style of 368 intake to look for or are they all pretty much the same? Would much rather pay $50 for a stock style intake than $300 plus for aftermarket.
What's so intimidating about it? So, Brian,,,, How does it run? What cam? Details!?!?!? Mostly found in this body style eldo: If it's 8 cylinders, and it's not a SBC, then it's the 368. The single plane alum is pretty easy to spot just by looking at it. Sometimes these engines will have some really bizarre heads and valve covers on them, as part of the 8-6-4 engines. The rocker arms were actuated by oil pressure, and a computer controled the setup. It allowed the car to acelerate with all 8 cylinders, but once cruising speed was reached, the computer could shut down cylinders making it into a 6 or 4 cylinder engine for fuel economy. The idea was sound, but the GM technology of the time wasn't up to the task, so it never worked properly. Most people just dis-connected the computer and drove it as a V8 full time. It's a really neet setup, and a couple people have re-engineered it to work properly.... But I'm getting off track. If I ever see another one in a junkyard, I plan to scoop it up and play with it.
no cutting required,and good gas mileage requires a good tune up. www.cadillacpower.com will help you out.
Pir8Darryl, great info! thanks You can also find the rear sump oil pans from the later 80/81 FWD Eldo and Sevilles with the 368 engines. The rear sump oil pans almost look like the sump was added as an afterthought. Here's a pic of mine, notice the weld line around the pan; If you are changing to a rear sump oil pan you will also need to change the dipstick and tube....and it will have to be put into the other port. The stock exhaust isn't too bad as long as you steer clear of the 425 exhaust manifolds, the right side is very restrictive I scored the headers off of Ebay a couple of years ago....got them for $150. I see the Caddy exhaust flanges for sale on ebay quite often if you want to modify BBC headers. I managed to come up with the stock port injection manifold, injectos, rails, etc awhile back and am in the process of building a MegaSquirt controller. Hopefully this summer and can get it all put together. I highly recommend Doc Frohmader's book, "Big Inch Cadillac" Its well worth the money. These are great engines! Bobby
Thanks for the great info so far!!! What are the options for budget valve springs and roller rockers? Can't see spendin a grand for a custom rocker setup..
Holy crap. "intimidating" You have got to be kidding. This info and the other advice offered in this thread is a gift for 500/472 fans. It takes years to accumulate the info here. Thanks to all for sharing. Thanks to the Caddy vendors for your R&D, products and efforts. I've used multiple 472/500 engines in my stuff over the years and just love the brutal torque that even a mildly modified one provides. Word of advice. Get your kickdown rpm adjusted low if your running stock rods. They do not like a leadfoot 2-3 gear late upshift.. Twice I lost a rod and did not learn There's nothing like a Cad low rpm burn out watching the tires jerk with cylinders firing.. Bad on the brakes though, especially if you like burn outs... Good memories. Thanks, Mike www.Customikes.com
I..... Might......... Know something. I could tell you, but I'd have to kill you if I did..... Give me a few weeks.
.... Heard of people usin the beehive springs from the chevy LS Motors with some machine work to the spring pockets and also some ford springs but not sure which ones. Also heard rumors of being able to use some type of ford roller rockers with abit of work but heard the thicker aluminum rockers won't clear the valve covers.
Metalshapes.... Rumor has it that the TH-425 FWD transaxle uses the QQ code internals similar to the T-400's behind LS-6 Chevelles and 455 stage 1 buicks. Just a rumor... But if your gonna build a T-400 and you need it to handle some serious HP, it would be worthwhile to tear the 425 apart and see if any of the HD internals could be of use to you Springs... Maybe Ford rockers.... Never seen it personally Valve cover clearance issues.... Yep... That's the problem we are running into. Aftermarket valve covers for the big caddy are almost non-existant. And what does exist is $$$$$$$ like their shit is made outa gold. I could spill the beans right now on a rocker option that costs $300, and can handle unlimited lift, RPM's, spring pressure, and HP levels,,,, but what's the use if it requires a $500 set of valve covers? I'm looking at spacers for the stockers. What I'd like to do is offer cast finned covers with the cadillac script..... But unfortunately, I know absolutely nothing about casting.
Heard one time that ford 460 valve covers could be used. Think it needed an adapter but can't remember. What's the rocker ratio for the 500?
I've heard about the TH425 having stronger parts. Not sure if I want to open it up or save it for a possible future project, though. About that tranny... It gets its power from a chain, and the Tranny is turned so its parallel to the Engine, right? So does that mean its turning in the opposite direction from what a regular TH400 does? Or is there something in there that reverses the rotation back around? Also, would a shorty tail ( like what they sell for Shorty Powerglides ) fit this tranny? Pretty sure I've seen a Shorty 400 Racing Transmission once... That way it could get a regular sliding driveshaft yoke on a gearbox that is shorter than the Engine...
It's just what I'v heard shooting the shit with the Bud's in the garage. Yes, the tranny does spin backwards, but the differences are in the valve-body. I'v been told the hard parts that hang off the main shaft will swap right into a standard 400, and that they are the best, most HD pieced GM offered.
Hey, regarding putting a manual trans behind the 472/500? I've found that an old chevy lakewood scattershield will actually bolt up to the back of the engine! The dowel holes and the bottom 2 bolt holes line up. The top holes will need a pair of simple ears welded to the top of the scattershield and the next 2 only need to be drilled in the flange of the scattershield....plenty of room for them. I've found the staggered pattern chevy starter won't work [no hole drilled in the block for the offset hole] and today I scored a chevy pickup-style 3 bolt [bolt-in from the front] starter but I can't get the starter snout to clear the inside of the starter pocket in the scattershield....looks like I'm gonna have to buy a caddy starter with the "straight-across" bolt pattern but it still looks like I'll need to clearance the starter drive-end housing or the scattershield pocket. I haven't figured out a flywheel yet [I know I can buy an aftermarket unit] and I'm gonna try to science out a way to bolt up the T-5 without having to drill the back of the crank for a pilot bearing...involves slicing part of the tranny's pilot shaft or/and possibly making a spacer between the tranny and bellhousing to get the length I need and buying a bearing that fits the shallow recess in the caddy crank.....well see To be continued........
I tried this old Scattershield on my 500 and thats about what I found out. Its aluminum, so I can move some stuff around for the holes that dont line up... And a starter bolts up to it. But thats as far as I got with that. Didn't do any measuring as far as offsets or flywheel toothcounts yet...
I'd only do it with an upgrade from these guys: http://www.gforcetransmissions.com/tran_gt-5.asp "Generally, it can be assumed that with the available upgraded mainshaft, the G-Force Street 5-Speed kit will handle roughly 600 hp or 500 ft-lb. or torque in a 3300 lb. vehicle running drag radials at the track with a moderate clutch upgrade. Obviously this is just a rough estimate regarding the power and torque handling capability, but it should give some idea as to what the G-Force Street 5-Speed kit will handle in your particular application." ~Jason
Mike Abssy at Schrader's Speed & Style has put a few 6 speeds behind 500 Caddy's. He can give you the info on what pieces make it work. He also sells adapters to put 331 - 390 valve covers on 500's. With those and a set of Offenhouser valve covers for the early engine you sholdn't have any valvetrain clearance issues.
I appreciate all the input on valve covers, but it's a little more complicated than that. What the hell... Here's what's going on. It's a 3/8" steel plate that completely covers the valve cover area. It's got holes cut into it for the valve springs to stick thru, and the push rods to come thru. It then has studs to mount BBC roller rockers. [or even stock BBC rockers if you wish] It has pedastals welded to the underside of it that bolt down thru the original valvetrain mounts, and it also uses studs that bolt down to the valve cover bolts for stability... The valve cover then mounts on top of the adaptor plate. So, stock VC's dont have enough clearance for the BBC rollers. Tall VC's designed for the caddy are $$$$$$$$$$$ To use an adaptor for "brand-X" VC's, an adaptor would have to be put on top of an adaptor that uses studs to secure it down... So I'd have to not use the studs, which would not be as strong, and the VC would end up being almost an additional inch off the head. If I did away with the studs, I'd have to drill "sinks" into the plate for the heads of the bolts to recess into so the "brand-X" adaptors could sit flush...... But would it seal up against the large recesses? Would the recesses remove too much meat making it too weak? It's easy enough to get out the slide-rule and hack metal to make something fit.... But doing it in an attractive package that is affordable is a challenge. If only someone made big VC's for the caddy that didn't cost $500.... *sigh*
Oh, and while we are on the subject, if you guys plan to run a stick, please please PLEASE dont skimp on the scattershield... Remember the "clutch explosion" link? http://www.jalopyjournal.com/forum/showthread.php?t=185297&highlight=clutch+explosion
Chris at http://www.cad500parts.com is working on new valve covers to address several issues, I believe... ~Jason
I'll have to check into that. The Cad Company [waaaaay back when Larry owned it] built my monster 552 cid motor. Larry was quite the cantankerous old fart. But he was knowledgable and a lot of fun once you got to know him. And he could tell some good stories too!
Wow... Thats cool... Is somebody making those, or do they only excist as one-off prototypes at this point?
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