I recently bought a 1967 Delta 88 four door sedan as a parts car and wondering if the engine, trans and rear end was worth hanging onto.

I've done some research and read some threads posted here. It appears the engine is a 425 with a bhp of 375.

I'm wondering if the engine is worth keeping along with the trans. which I think is a TH400 but unsure about the rear end ratio and if it might be useful in another build?
In a thread I just read, the rear end could be a 2.5:1. I am pretty it doesn't the towing package.

Thank you for any comments.

 

Yes, the 425 is a good engine. If not as a whole, at least the steel crank.

 

Transmission probably is a TH400 and should be a variable vane/switch pitch torque converter system. Please don't just scrap that motor and/or transmission, someone wants it....

 

There’s two ways to think of the 425:

1) It’s a .125” overbored 400E engine.

2) It’s a short stroke 455 with a forged crank and 7 inch rods.

Either way it’s a great engine.

 

375 horse version is a Starfire engine which was available in 1967 Delta.

Look for "Starfire" callout on the air cleaner, 4 barrel carb and dual exhaust. Rocket (2bbl single exhaust) or Super Rocket (4bbl single exhaust) are more likely though.

Course even a 2 barrel single exhaust 425 made 300-some horsepower.

425 is arguably Oldsmobile's overall best engine. Displacement, power and efficiency. It beat everything else GM had at that time. Put it this way. It was the only GM engine that didn't require a smog pump to meet California emissions, though all Cali-bound Oldsmobiles had them. Probably just to shut CARB up.

 

They had stronger blocks from 65-67, in 68 they changed the casting materials. Can't reference anything for that but I've read it in a number of articles. Also I believe they can take higher rpms than the 68 and up engines. As someone has already mentioned they have steel cranks.

 

Your 1967 block is the best of the 425's, imo. It is the smaller lifter, 0.842 lifter plus 39° cam bank angle. As always check the angle, 39 vs 45. One never know who changed what engine into these cars. Every 1967 425, I've checked was 39°. Jmo.

 

they quit building 425 in 67,68 they went to 455. i believe your thinking of the 400 for 68,it was different than 65 67

 

Wasn't '67 the last year for the 425? In '68 they went to the 455.

 

I was just referring to materials used to make the tall block Olds engines, not necessarily the size. I picked up a couple 425's for use in one of my 66 Cutlasses not only because they are period correct but because after talking to a number of Olds guys they said the 455 blocks weren't as strong and they stopped making forged steel cranks in 67. Even though 455's are easier to find, at least where I live in the boonies, the 425 is the stronger engine. It's a bummer they never put them in mid size cars.

 

Sorry, this is an urban myth that refuses to die. There is no difference in block metallurgy.

 

Interesting, I've not heard that before. I'll have to talk to one of the guys that told me that and find out where he got it from. I know I've read it too. Here I was thinking my 425's and 330's were somehow of superior strength. Before I joined this forum my access to Olds info was limited.

 

No one that claims the metallurgy is different ever has any proof, or Rockwell hardness testing data, or anything that actually backs up the claim. A change is far more likely in the 1977 time frame when Olds went to windowed main webs on all gas engines and lightened the head castings as well.

 

The 425 is the best engine because of its balance. The shorter stroke and steel crank allow it to rev better than a 455. This just my opinion, but I'd like to see someone prove otherwise.
To quote a long time, drag racer friend: "The problem with Oldsmobiles (engines) is they have big, heavy rods and big, heavy pistons"
It makes a lot of sense if you think about it.

 

weren't the 330's and 425's factory balanced,my 67 vistacruiser and my 66 toro had the smoothest running engines i have ever had.

 

Forget what everyone else says here, the 425 is garbage, but I will do you a BIG favor and take it off your hands for a few hundred dollars.

Seriously, though, it is a GREAT engine!

Here is a story of a very steerable build of a 425 by Hot Rod.

https://www.motortrend.com/how-to/cc...elbrock-heads/

 

"Originally Posted by Cossack View Post
They had stronger blocks from 65-67, in 68 they changed the casting materials."

If there was a change such as higher nickel it would be evident in the sound produced by the cutting head when boring. One well known example of this is 1957 and 1958 Chrysler 392. You can hear the difference when boring cylinders. Geez over the years of arguing this on boards it seems no one actually points out a detail like this based on experience. The internet has caused bad information to become perpetual.

 

You’ll also notice those who call it an old tale, also offer nothing.

 

Gotta love this:
We'll revisit the 425 once it's installed in the Cutlass for evaluation and to watch Navid deal with his newfound traction deficiency.

 

Glad to hear it's steerable. I'd hate to see them go to all that effort to build an engine and then drive the car into oncoming traffic.

 

Is there anything special about an Olds 425 engine?

Just about everything... In essence it was the biggest most powerful engine Oldsmobile ever produced that was not compromised by cost cutting...

It's part and parcel to the Toronado being Oldsmobiles Halo car. The very embodiment of Oldsmobiles greatness.