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Cadillac 500

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stef_dogg

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What would it take to install a cadillac 500 in my 76 blazer? I would like to use chevy 454 throttle body injection on the 500. Advance adapters said to use a 2wd cadillac version of the TH400 and cut part of the output shaft off, to mate to a 4wd tcase. Does the 454 distributor fit into the cadillac 500? What are some specific issues I would need to address? I think I could get everything else to work. I am currently running a 350 with throttle body injection.

Thanks

Stefan.
 
I haven't done it, but from what I understand you can use the case from a Buick, Oldsmobile, Pontiac (BOP) case with your 4x4 T400 guts and output shaft to mate it to your transfer case. Maybe someone else can give you more insight though.

Kris
 
a few choices..

You could use an adapter to bolt up the caddy motor to a chevy tranny--Jegs and Summit sells them,they cost about 70 bucks...or you could use a later caddy rear wheel drive TH400 that has a short tail(you may have to cut off some of the output shaft as the other post said,and it will bolt up to a transfer case with the TH400 input...)-Buick,Caddy,Olds,and Pontiac trannys share the same bellhousing pattern,any TH400 from them with a short tail will work..(Hmmm---guess CHEVY is the "odball" when it comes to gm bellhousings! :blush: )

-the TH400 they put behind the 500's are usually the "longest" tailshaft style ever used,and they have a goofy caddy only bolt pattern on the tranny mount(easily adapted with a flat plate the right size)--but that super long tailshaft is the bummer,you need the "short tail" style from one of the above vehicles or the adapter to mate the caddy to the chevy tranny..

.I've heard the adapter route works pretty well,it minimizes the hassle of changing the existing tranny and drivetrain,and it moves the motor a bit foreward,which gives more clearance at the firewall(some trucks the caddy motor hits the firewall,behind the drivers side head,and you need to massage it a little,the adapter helps that to miss--)

trucks I've seen with 472/500's had used the existing TH350 tranny by using a TH400 coverter(you have too,caddy flexplates only have TH400 bolt pattern,not both like other GM's--) the TH350's seem to live behind them pretty well unless you beat it bad or use it to tow super heavy loads... :crazy:
 
What intake manifold are you going to use to instal that EFI? You won't find a bolt-on unless you go custom.

Just a note, AMC has the strangest of all TH400 cases. The bellhousing is round.
 
He's talking about the 454 TBI, so wouldn't that just be the same Q-jet to TBI adapter that GM used factory for a few years?
 
Well thinks for the info so far! What intake will work? And whats this you say about a factory adapter from QJet to tbi? And what about the distributor? Knock sensor? Do you guys think that this is possible to make function correctly?

Thanks
 
You can use any one of the aftermarket Caddy intakes with an adapter to mount the BBChevy TBI unit to. If you use the stock Caddy pancake intake you will be using an adapter for a Q-jet intake as the caddy's come with 850 cfm Q-jets. More than likely the intake you will want to use is the edelbrock caddy intake. The guys on the site I posted will be able to give you much more insite on anything to do with that engine.
 
I will guarantee that just bolting a 454 TBI setup on a Cadillac will leave a LOT to be desired. Look at getting into burning your own PROM's, it will take a bunch to get it right.

Knock sensor is different based on displacement, "tuned" if you will. Oddly enough, different applications moved the sensor around on the engine block, so there has to be some "fudge factor" to them. You will probably have to start finding info on how people solved that problem when converting other V8 motors, like Buick, Olds and Pontiac that were never injected. (although the Olds 307 used a knock sensor about 1988-90, carbed though) I'm sure a few have done it, just have to find the info.

Thirdgen.org MIGHT have some info on doing what you are asking, perhaps not with the exact same info, but the information WOULD help.

As similar as the GM distributors are, I'd be surprised if you couldn't, with some work, make the guts from an injected distributor work on the Cadillac one. I don't believe any of the GM distributors share the same overall length, although everything else (diameter of the shaft, internals) seem to be very very similar. I've been told the Olds 307 CCC distributors will work with an injection setup, so that might be another parts source.

IIRC Cadillac ran some injection in the late 70's, but it wasn't very good. However, once again, those distributors might have ended up being the prototypes for the later CCC and TBI/TPI distributors. (Cadillac always being a flagship car, getting the fanciest gadgets) All cars were CCC by 1981, and I *think* Cadillac actually adopted CCC in some applications in 1980. Not familiar enough with Cadi to know if any of the 472/500 family (any that would share the distributor) were still around in 1980. I suspect no. :(
 
Caddy parts

The distributer on a caddy is shorter than a sbc, so you have 4 choices for a distributer, MSD, Accel (supposed to be out now), stock Hei or points.
Fuel injection was '76 for sure (on the 500's) and some 425's and 368's (77 and later) so its not bad just not that good. The FI manifold from the 368 or 425 will bolt on a 472~500 but its kind of like putting a cork in the system, it has a smaller runner cross section. The place to start getting those parts from is Maximum Torque Specialities www.500cid.com/ talk to Al, he has lots of used parts in stock. What are you going to use for an oil pan? Most caddy's came with a front sump pan...that will hit the front crossmember or the diff. The eldorado pan is a rear sump but not that easy to find anymore.

You might guess that I'm getting ready to do this swap myself, here's my plans. The blazer is getting a 4 inch lift first, the fedex/ups parts fairy was here today with the first box( ORD kicks butt!!!) after thats in then its time to look at engine fit.

The front engine Xmember is going away and I'll build a new one that will move the motor mounts ahead 4 inches and and act as the Xmember at the same time. My K5 already has a th400 tranny in it so I'm going the Summit/Jegs adapter route to mate the engine and tranny. The exhaust I want to use is a set of headers from a 460 ford to fit a 76' van, drivers side will be easy with these so I'll probably have to massage the passenger side to get it to work, (the bore spacing is close between the ford and caddy just seperate the tube from its neighbor,cut the flange, the bolt pattern is the same on the port, the biggest pain is the port shapes are different, I'm working on that.

These are the build plans for my 500, rering and new bearings, deck the block to zero on the stock pistons. Bigger cam, haven't decided how big yet. The heads are the low compression 120cc open chamber with a 1.94 intake and 1.6 exhaust (stock) that will get some mild porting and bigger valves, 2.11 intake and 1.77 exhaust and shaved .025 to help compression. I'm looking for about 375hp and 550 lb/ft of tq, with peak tq to occur at around 2500rpm.
Hope this helps
George
 
I will have a caddy in my 'burban once I get to that point. I guess I am at the same point you are... I havea 6 inch spring lift sitting here waiting on the dana 60 front and 14b rear. I still have to get a few other things though...
 
will an aftermaret distributor work with the tbi injection and computer? Are you going with carb or injection, if so what setup are you going to run?

Thanks
 
the caddy's came w/ their own efi system.

i am building a 547 stroker 500 for my k5 now. the way i see it the ford efi from a 5.0L would be a better choice for the efi swap. those computers are easily modified & there are tons of aftermarket base for those systems. it will not be as cheap, but i believe from a performance standpoint it will be much better.

u might want to look at some of the universal efi systems Howe sells also. i have a friend that runs one & he likes it a lot.


as far as putting a 500 in your rig it is a nice fit. i cut the factory crossmember out built my own from tube. used a caddy 400 & put the gm 4x4 guts in it. eldo oil pan. i cut 4 plates & bolted them to the block were the engine mounts go & used them to sandwich a spring eye bushing. i put the engine as low & far back in the chasis as i could get it.
 
a couple of picsof my swap


13389P8030023.JPG


13389P8020015.JPG


13389P8020016.JPG
 
About the fan

Boz42 what fan are you using? If its the stock are you lined up to center the fan to the rad?
Like your mount, thats about the same that I'm going to do.
George
 
So after reading all the posts? What is the beat way to Fuel inject the 500. After I switched to TBI on my 76 blazer, I could never go back to a carb. Lets hear the pros and cons of several options?

Thanks
 
Well I am in the same boat as you... I know that I will want to have mine fuel injected instead of a carb. There are many guys working on different types of FI setups on the cowboy 7 site. I will always run my caddy questions by them to get the best ideas on that engine. Most all of them also post on the Al's MTS site as well.
 
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