Olds 425

[sldwys]

I bought a 67 olds 425 engine about 9 to 10 months ago. Paid 300 for mine.
I dont recall what heads mine has. As others have said, if the crank is good, it's worth 250.

What are your plans for the engine?

Flexplate can be found so don't let that scare you. I also bought my 425 with the 2 barrel intake. A member on here hooked me up with a 4 barrel intake. If you plan to keep a stock hood, you will be limited on intakes... maybe even locked into a stock intake but dont quote me on that.

If you have the budget and feel comfortable getting the 425 into your car... go for it.

One last question. What does the rest of your drivetrain look like. Adding the power from a 425 could mean exhaust, transmission, and rear end upgrades.

Good luck. Let us know if you get it.

I just want a bigger olds engine in my 442. So plans would just mildly build the motor. No clue how or with what. My car is completely stock, so how much upgrades would be required if the motor is kept under 500 hp.

Are aftermarket parts to do a complete rebuild available? I’m all new to Oldsmobile and the g body. I just figure 250 for a bbo is worth it.

 

[fleming442]

Talk to someone knowledgeable with building Olds. Clearances are paramount, especially piston to bore (.003-004), so don't just take it to Joe Schmoe because it'll be treated as a Ch*vy and probably not live long. The 425 will be plenty of power in stock form, but will benefit from intake and exhaust improvements (headers, intake, etc). It can get pricey quick, so choose wisely.

 

[sldwys]

Talk to someone knowledgeable with building Olds. Clearances are paramount, especially piston to bore (.003-004), so don't just take it to Joe Schmoe because it'll be treated as a Ch*vy and probably not live long. The 425 will be plenty of power in stock form, but will benefit from intake and exhaust improvements (headers, intake, etc). It can get pricey quick, so choose wisely.

Yea I’ve been researching the differences on olds vs Chevy. And understand not just anyone can rebuild. I’m just slowly collecting parts and wait to get to a certain point then go from there.

 

[olds307 and 403]

The only upgrade in the drive train will be the TH2004R trans. It will probably need hardened pump rings, stator, bigger boost valves, servo and probably a billet forward shaft and drum. A deep pan and 700R4/4L60E filter is also a good idea along with a trans cooler. Also if your radiator is stock, expect to replace it with a large 2 core or 4 core aluminum rad.

 

[Alerch]

I have the little brother 400 E block in my 86. Great engine for cruising around, if you plan on racing it all just remember these Olds engines are HEAVY.. They do look good in these cars though.

 

[olds307 and 403]

Another thing, do not run your factory exhaust, unless you want to loose 50 hp. Even the BBO performance W/Z manifolds give up 30 HP over headers.

 

[sldwys]

The only upgrade in the drive train will be the TH2004R trans. It will probably need hardened pump rings, stator, bigger boost valves, servo and probably a billet forward shaft and drum. A deep pan and 700R4/4L60E filter is also a good idea along with a trans cooler. Also if your radiator is stock, expect to replace it with a large 2 core or 4 core aluminum rad.

What about the frame?

 

[sldwys]

What about the frame?

Anybody have any videos of the 425 idling with a cam? Can’t find anything worth a dang on YouTube.

 

[sldwys]

Another thing, do not run your factory exhaust, unless you want to loose 50 hp. Even the BBO performance W/Z manifolds give up 30 HP over headers.

What headers will work for this 425 and the g body?

 

[fleming442]

Anybody have any videos of the 425 idling with a cam? Can’t find anything worth a dang on YouTube.

Look up Dan Macal in Florida. He stuffed a 425 in a G and beat the snot out of it.