425 heads on a 500 and other questions

bamabob

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cadillac512 said:
bamabob said:
How about rerouting the coolant flow for the heater. Can I put a freeze plug in the head and pick up water elsewhere?


Yes. I suggest drilling the block just below the thermostat on the right hand side. Tap it to either 3/8" pipe or 1/2" pipe and install a heater hose nipple. That's where the '70 engines ran the heater supply hose and it works well. The 425 may even have a flat surface there like the later 472/500 engines do.
I just checked one of your pics and your 425 may already be drilled and plugged there....is it?
http://rides.webshots.com/photo/1490854 ... 6353EbuNAY

Terry

Terry, you are right. There is a tapped and plugged outlet there. Looks like 3/8". Thanks for taking the time to research this and reply. Also thanks for the compliments on my car.

Bob
 

hertzdaddy

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bamabob said:
For all these reasons I have a couple extra 200 4r's on hand. I had not seen the 600ft/lbs rating though. I was thinking once you got past 500 you were in no man's land. One of my extras is a zero mile Monster transmission that a friend gave me awhile back. Not sure which version it is but he bought it for his GN Buick when he was planning to go big but never got it in before he sold the car. Didn't have to think twice when he offered it to me.

http://racetransmissions.com/store/prod ... ts_id/208e

Oh the 200 46 is same length as TH350 and the same driveshaft fits as is. Just move the cross member back and your done.


Link is for a 200-4r rated at 275HP. Not exactly Cadillac material.
 

bamabob

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hertzdaddy said:
bamabob said:
For all these reasons I have a couple extra 200 4r's on hand. I had not seen the 600ft/lbs rating though. I was thinking once you got past 500 you were in no man's land. One of my extras is a zero mile Monster transmission that a friend gave me awhile back. Not sure which version it is but he bought it for his GN Buick when he was planning to go big but never got it in before he sold the car. Didn't have to think twice when he offered it to me.

http://racetransmissions.com/store/prod ... ts_id/208e

Oh the 200 46 is same length as TH350 and the same driveshaft fits as is. Just move the cross member back and your done.


Link is for a 200-4r rated at 275HP. Not exactly Cadillac material.

Yeah, I linked the mild version in error but they offer a heavier version. Here is the correct link http://racetransmissions.com/store/prod ... cts_id/185.
 

PROSTOCKTOM

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You guys are bearing a deadhorse on this 200R4 stuff.

The bottom line is If you want a 200R4 to half way have a chance of living behind a well built 500 it's going to take

around $1500 worth of hard parts to do it. But my transmission shop friends says not to expect it to not break parts

every now and then. It will not be bullet proof even with the kitchen sink included in the build.

Tom
 

cadillac512

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So Tom,are you saying a good TH400 and a gear vendors would be your top choice? Or would you go for the 4L80E and a diesel or custom controller?

Terry
 

PROSTOCKTOM

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cadillac512 said:
So Tom,are you saying a good TH400 and a gear vendors would be your top choice? Or would you go for the 4L80E and a diesel or custom controller?

Terry
Turbo 400 and a Gear Vendors any day of the week.

I'm a diehard Ford guy, but my 49 Coupe with the 514 in it has a JW Bellhousing with a SP Turbo 400 on it.

There's one reason I use a Turbo 400

It Works Better Than Anything Else If You Have Big Torque

Tom
 

bamabob

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PROSTOCKTOM said:
cadillac512 said:
So Tom,are you saying a good TH400 and a gear vendors would be your top choice? Or would you go for the 4L80E and a diesel or custom controller?

Terry
Turbo 400 and a Gear Vendors any day of the week.

I'm a diehard Ford guy, but my 49 Coupe with the 514 in it has a JW Bellhousing with a SP Turbo 400 on it.

There's one reason I use a Turbo 400

It Works Better Than Anything Else If You Have Big Torque

Tom

Can't argue with that. If my car was seeing any strip action at all the 400 would go back in. I think stock they will handle 550 ft/lbs all day long. But in my case with just a cruiser I'll live life on the edge with the 200 4r (and worry if it will break every time I nail the throttle)

Bob
 

bamabob

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Just wondering - who all is running the 200 4R behind a 425/472/500. And who has done this and broke it?
 

PROSTOCKTOM

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Honestly my transmission shop friends tell me that other than the bellhousing issue which has now been solved that running

a Ford AOD is a way better transmission than using a 200R4. Plus a well built AOD and convertor will only cost $1300 plus a

aftermarket bellhousing. I plan on using a AOD with my LYB stroker in the other 49 coupe someday.

And the AOD has lots of torque capacity and you can use the stock 2.46 first gear or the gear set from an 4R70-W which is 2.84 first

The bellhousing is made JW Performance part # 92450-AOD about $240-$250 depending where you buy it.

If I wanted a 4 speed od for a Cadillac engine this is the route I'd take, no computor needed, fairly light weight package.

Tom
 

PROSTOCKTOM

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dave brode said:
fwiw, I know a couple of guys that run those AODs behind semi stout stuff.
I know one that was built by my friend that is behind a 1200 HP Twin Turbo 400 inch Windsor and another they did

that is behind a 598 in a 1968 ERA AC Cobra that really pounds the pavement.

I was just at the shop tonight in the hard parts room looking at all the pieces.

Few hundred dollars in the 1 piece input shaft and that's all you really need in aftermarket hard parts.

He told me unless I plan to cruise a lot to just stick with the SP 400, not that you couldn't do full power up shifts

with the AOD , but he told me I can burn a lot of gas for the price difference between the two.

Tom
 
G

G-272938

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I have a 500 Cadillac what will cause it to blow out the water before motor gets hot
 

Caddylackn

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It would be best to place this as a new subject and a new post with a description. I am not sure why you added this to a 12-year old dead post on 425 heads.

Can you tell us where the water is coming out of? Heads? Water pump? thermostat? Radiator cap?

The first thing I can tell you, is to make sure it is a Cadillac 500 thermostat and not a chevy thermostat, there is a big difference.
 
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