425 caddy,anybody know anything about them?!!!

i was recently working on a baked 429 caddy but got a call from a friend with a running 425. im trying to figure out what kind of hp/trq this things got.everywhere i look shows me net hp/trq(at the wheels)of 180/320 id like to know even an approximate number at the crank.i want to make sure this things got some "cahonies" out of the box with some mild work(cam,exhaust,intake,carb.)

 

i forgot tomention the motors out of a 1979 coupe de ville rwd.

 

www.cadillacpower.com

Everything you ever wanted to know...

 

ramblur is right!
go big or go home!

 

all GM cars lost compression after 1970 and all 70's and early 80 were the pits.
if that wasn't enough they changed the way HP was rated to try to confuse the public (not hard to do)

 

I've got a 425 that is being used in a '49 Hearse. It's the lil' bro of the 472/500. Not a bad motor, plenty of torque, and if it's in a lighter car than the deville it came out of it'll scoot real nice.

 

the HP rating change in 1972 took about 30% of the power out of every car....and there were also real changes to the engines that took out some more (compression, etc)

An engine doesn't know what year it is though, so there's hope to wake it up with some minor changes. With today's gas I would not bother trying to increase compression, but you can improve cam timing and exhaust (duals and headers) for a notiecable gain. It's still a good sized engine, so it should be ok.

 

I've got one in my 52 Chevy. I put it together as recommended by the Cadillac gurus on the cowboyseven board and they say I should expect at least 400 foot pound of torque at 2500 or so rpms.

http://www.cowboyseven.us/forum/index.php

Basically a stock bottom end, minor port job just to clean uo the casting and smooth out the bumps, cam ground for low rpm torque, a good timing set and intake and exhaust manifolds from a 500 since they flow better. I haven't driven the car on the street yet but just punching it a little in the driveway results in a traction issue. It is backed with a 200 4r trans, hopefully built tough enough and a 3.42 geared w/posi 10 bolt. If you are wanting a cruiser with a little kick to it along with a bit of economy compared to the 500 you should be satisfied with the 425. If you want a stump puller get the 500. Also the 425 is about the same weight as a SBC and the 500 is only about 75 pounds heavier. The 425/472/500 are identical on the outside but the big inch motors have more metal in the block for strength.
Hope this helps.
Bob