Hi Olds family!...your fellow brother Nick here from Michigan building and restoring my 1978 Delta 88 in memory of my late wife who passed away January 7th of this year...now I have a chance to pick up this 425 off of a guy locally for $400 dollars...I initially wanted to build a 455 or do the unthinkable and splurge for a Rocket Racing block...but everyone has one of those on their wish list...let me know what you guys think of building the 425 or should I keep searching through hell and high water for a 455 in my area or just shoot for the RR block and build it over time...this isn't a rush project by any means and would love to hear your input because I plan on building a wolf in sheeps clothing while keeping a pretty much stock appearance with the interior and exterior of the vehicle...thanks everyone!

 

425's are excellent motors. Unless there is something wrong with it grab it. Check it as you would check any other used motor. All 425's are steel cranks.

Lifters and camshafts can be difficult or $ to source.

Again if it meets your criteria, grab it fast.

Sincerest condolences for your loss.

 

Decide what you want. A 455 has the 39 degree block and cam choice off the shelf is better. A 425 could be 39 or 45 degree cam angle. A 425 can be a 455 with a 455 crank, connecting rods and minor work on the block.
I wouldn't give more than a couple hundred for the 425. If it was me, I would pass on the 425 and find a 455.

 

What’s your hp/tq goal?

 

I'd get the 425. It's a great engine and as stated in a previous post it has a forged steel crank. The 39 vs 45 cam thing isn't that big of a deal.

 

I agree with the others about the 425. Think of it as an overbored early 400 engine. Those were awesome, and 25 more cubes is even better.

 

I really appreciate the condolences for those who commented!...he spins the motor over to keep things moving he told me so that's a good thing...my goal is to break 500 horsepower...just making sure this would be a good foundation for the build...I really like what RR has done with that block...And I also know you can easily end up with a 20k motor with one of them but the RR block is the last option I have on my list.

 

In order to make even just 500 with the 425 you’ll need really good heads and a decent check book. Just sayin.

 

At least one head is a C from the pics. If that head is original would C make it a '67 and likely a 39° block?

 

Nice looking car, the best styling of those late 70's to mid 80's Delta 88. If it is a good standard journal 425 steel crank, it can be offset ground and use BBC rods for more cubic inches. Good luck, sounds like it will be very fun.

 

425 vs 455 HP expectations

​​​​​​What are reasonably achieved HP goals for 425 & 455's with iron heads, streetable with an automatic transmission running on pump gasoline?

 

Well, 1966 Toronado made 385HP. So that's a minimum with a decent rebuild. It terms of reasonably achieved, it depends what compromises you are willing to make? Would you run a low real axle ration, could you live with a high stall torque converter, Does it need to behave well on the street? Can you manage without Vacuum at idle? Would you be willing to spend on a hydro boost system? Does it need to behave when it's cold? How much money are you willing to invest? Reasonable means something different to different people.

 

that's a good looking car. is that an 8'' rally wheel in the back or 10''? as for the motor, no replacement, for displacement. parts for the 455 are probably easier to get as one person stated. good luck.

 

Thank you guys for the condolences on the wife and compliments on the Delta!...she's as solid as they come beside some patina from the southern heat now she's in Michigan...I know there's a lot of reliability questions and fuel choices you guys are concerned about...and like I said this isn't a 1 year build I'm planning...I want to be able to go to cruise ins and meets with the car but the goal I'm aiming for is to go after Dodges large cars that are on the street now so that's why I'm thinking the 455 would be a better choice...the car will be in stock appearance inside and out adding gauges of course and a good tire out back and it will get some quarter mile passes as well but not a strictly track car....as for the size of the rear wheels I have to check...I just got the car and haven't pulled the caps off yet but if I were to guess they are 15x8.

 

Throw that 385 figure out the window. That was a gross number made on reeeeally good gas back then.
I’ll stick with my original post. For 500hp be prepared to spend some money..

 

Welcome Nick, sorry for your loss.

Nice car ! Full size 2 doors are automatically cool in my book. And 425s are arguably Oldsmobiles best engine ...

Tremendous upgrade over anything available for that Delta when new. I wonder if a standard height intake would get that Toro build to 400 gross HP on an engine dyno...

Nick as Cutlassefi mentioned and as a professional engine builder he knows. That extra 100 HP over a Toro 425 is going to cost you. Being that the Toro was factory maxed out to begin with. You will need to go above and beyond. But I think it's definitely worth it.

 

I think its worth it too!...I plan on making the Lansing meet but how cool would it be to see a tastefully done Delta 88 with big power that has a damn near factory appearance inside and out with a big block Olds under the hood cranking out some big power...got the ideas floating around in my head and like I said...QA1...Southside Machine...Wilwood...Strange...just to name a few...I know those Hellcats and Scat Packs weigh a decent amount and figuring my power to weight ratio and so on and so forth but I want to show these young guys not to underestimate us older fellas...everyone doing LS swaps or dropping Chevy engines in these cars and that's not what my plans are...it will run on pure rocket power!...I'm sure there's a Delta drag car out there but nothing like what I have planned!

 

500 HP is not out of reason with Iron heads and 425 CI. You will have to look at your budget as it won't be a simple rebuild. You will have to pay attention to the cylinder heads, this will cost if you don't know how do it yourself. It would be better to pick a performance goal with usage. You might not need 500HP. If you do build 500HP remember your entire drive train and chassis will need to match$

 

We think alike!!!

I have always wanted to build a early 80s 2 door B body with a turbo 455. Quiet exhaust, with the wire hubcaps, A/C, functional cruise, maybe curb feelers thrown in for the added “geezer” look. Just like my 66 Nova with the Grand National drivetrain, or the 65 Coronet, or the Duster, unfortunately it will probably never happen.

Build the short block stout. You can always upgrade heads later. Build the engine to work well for the 99% of the time your just cruising. If the 1% isnt enough, use some of the huge trunk space for a nitrous bottle.

I would think 425hp would be easy to make with a 425. Put some decent suspension on the car, I bet that’s more than enough to make the mustang and Camaro crowd look pretty stupid. I have spent enough time at the dragstrip to see lots of disappointed Camaro/mustang owners when their 12 second car barely breaks into the 13s.

 

I feel I may have a bit to offer on this front. About two years ago, I started the build of my 425. Mark here supplied me with a 45 degree roller cam, lifters, Mahle pistons, and Rocket Racing Scat rods. I'm running Edelbrock heads & intake, harland sharp roller rockers, hooker headers, ATI balancer, Canton pan, ARP hardware, etc. I had the crank internally balanced (neutral balance), bore, align hone, crank ground, crank machined for a pilot bearing, etc, etc. I have about 10k in the build with the goal of 450 HP. That doesn't include the fuel (Sniper ~ $2k) or ignition system (Dual Sync ~ $500 including distributor, wires, coil). Car just got on the road - working out kinks before eventually taking it to a dyno to get the EFI fully tuned.

So yeah - relatively expensive to do. Could definitely be done cheaper, but could also cost quite a bit more depending on what you do (my heads are untouched - out of the box).

 

Finally found a 455 locally!...messaged a guy about a carburetor and he's currently restoring a Cutlass not sure what year but older fella and he was nice enough to let me know that his friend has a 455 for sale!...so I will be purchasing it from him here soon...waiting til I get off work to talk to him over the phone...I'm very excited!...I think the wife had something to do with it from Heaven...here's the picture he sent me...I'll post more as I get them!...not sure what heads are on it either but I'll find out and let you guys know!

 

Just a thought on goals for this engine.

Engine is going in a good sized, weighty car (A body territory), might a goal of 500+ ft/lbs be a bit more attainable, easier on the bank acct and likely provide better driving manners and acceleration? Maybe mid to high 500’s torque with mid to high 400’s for hp? Of course at that point the driveline might be approaching a tipping point but you’d know soon enough if anything is overwhelmed. Im sorry to admit I don’t know what the driveline consists of, is this is a TH350 trans w/ 10 bolt corporate? You’ll need limited slip either way, some gear would help a lot too. If it’s a 200, you’re gonna need a well built 200-4R or sturdy TH350 to take some power.

Like I said, just a thought that crossed my mind reading through the thread, not trying to muddy things. I know 500 hp is a popular goal but on the street, in these 2 Ton Tessies, torque is usually gonna bring satisfaction. I don’t know the average driving conditions of your stomping grounds, but how often can you stretch one of these cars into the upper rpm range, never mind in multiple gears?

 

I haven't got everything down on paper yet but everything is going to be bulletproof pretty much and its not a overnight thing...but I plan on doing some soul searching maybe even contacting a few companies as far as one of their rear ends would cost a trans from TCI or PA and Eagle for one of their stroker kits...money isn't a problem just getting the right quality parts / machine shop etc. are going to be carefully selected just getting started here so bare with me...the guy I'm getting the engine from has a 11 second 455 as well so I'm going to talk it over with him as well because he wants to help me with the build..

 

Sweet ! I'm excited for you. Look forward to following your progress.

Sensible, take your time and enjoy the experience.

I only wish you could throw in the 455 as is to get a baseline. But I understand it's an additional time and money consuming endeavor.

 

why fo the valve covers look “Buick ish” I know it’s not a great picture and my eyes aren’t what they used to be but that valve cover looks strange , it could be the aftermarket valve covers ? But it looks more like a Buick 455 then an olds check all the numbers and head letters etc I do hope I’m wrong and if so my apologies

 

Buick 455s have angled plugs? Something just don’t look right though

 

A Buick 455 has its distributor on the front of the engine in the timing chain cover. You can see the opening for a distributor at the back of the block in his picture.

 

yes indeed, thank you , the eyes are the second thing to go !!! lol but don’t the valve covers look odd? Maybe it’s me that’s odd lol

 

The valve covers look like tall Moroso covers.

 

thats exactly what they are.