Bane

I have the opportunity to buy a full '77 olds 350 for a good price, but i was told that it wont fit into my 1986 t/a motor mounts for the lg4 motor. Is this true? Is there a way to get around this? has anyone heard of anything like this?

Randy82WS7

you will need oldsmobile mount setups and exhaust manifolds and pipes and other things tooo

chevy is different than the rest,

you need donor parts from a pontiac or olds or buick v-8 car
plus your tranny is chevy pattern and wont accept a BOP engine

also you need a BOP pattern tranny too

http://images.google.com/images?hl=e...lhousing&gbv=2



good luck

j dezzy

iTrader: (12)

I've never put an olds engine in a chevy...but I did take a 72 chevy nova 350 and put it in my girls 87 olds. bolted up to the stock motor mounts. I never new there was a difference. Had a new turbo 350 tranny though. so couldn't even comment about the tranny mating up or not.

RacerXXX

The only thing other than the motor mount issue would be go fast parts, Olds aluminum heads are expensive compared to SBC stuff. I think you'll find everything is a little more costly and sometimes harder to come by.

JDezzy: If I'm not mistaken Olds/ Pontiac had their own block up until 1981, after that everything went corporate gm. A 72 Nova would have a SBC just as an '87 Olds would.

j dezzy

iTrader: (12)

ah, ok. that explains that. the only other times I've messed with an olds was to put an olds motor in one. thanks for the info.

sofakingdom

iTrader: (1)

A 77 Olds might have just about anything in it. Chevy and Buick motors were both quite common, in addition to Olds.

IIRC that was the year that GM got sued by some guy that HATED Chevrolet and loved Olds, so he bought an Olds. After he'd had it for a while he went to buy parts for it or something, and discovered that the 350 in it was a Chevrolet. He sued GM. GM's repsonse was something like "we had to put a Chevy engine in your Olds because we had already used up all the Olds motors in Cadillacs". {insert loud obnoxious buzzer sound} WRONG ANSWER!!! They lost the lawsuit.

Buick, Olds, Pontiac, & Chevy all had COMPLETELY DIFFERENT, incompatible 350s. NOTHING WHATSOEVER will interchange among them except for some of the electrical accessories and maybe a few of the bolts. The BOP motors used one bell housing bolt pattern, the Chevy engine used another. Engine mounts are different.

Look at the motor. If the water pump is a huge flat thing covering most of the front of the motor, and the oil fill is a tube sticking straight up in front of the carb, it's an Olds motor. If the distributor is in the front, it's a Buick motor. If the timing cover is sheet metal and the water pump stands up on 2 legs and extends over the timing cover but doesn't touch it, it's a Chevrolet.

Even if it's a Chevy 350, it would be the ULTIMATE smogger dung. The 4-barrel version would have been "rated" at 180 HP or so. Very very slow and inefficient, basically right in the middle of the absolute worst year range for a complete motor core. The block, crank, & rods are ALL that's worth anythign from it; all the rest needs to go in the trash.

If it's not a Chevy, pass. Even if it was totally free, it'll cost you more trouble and money to put in and make work, than buying a Chevy motor for it at normal market prices. You'll have to change out EVERY PIECE that touches it, including the exhaust system and transmission, if it's not a Chevy.

KrisW

iTrader: (5)

I've put an Olds 350 in a third gen before (a Buick 350 as well) and it is definitely 10% inspiration and 90% perspiration.

I can give you the basics on what it takes but you should search the engine swap forum. I wrote it up once and a guy from Chicago put one in his 86 Camaro as well and did a pretty thorough posting.

You should only do this swap if you are "romantically" inclined towards B-O-P engines (like me.) From a practical standpoint, a chevy small block is the easiest and cheapest way to go. Honestly, if you already don't see the huge roadblocks ahead without posting, you're not ready for this.

Oh, and if it is free (or nearly) then let ME in on the deal!

Good luck and let us know what you decide!

KrisW

iTrader: (5)

And just to clear up a little misunderstanding from above, Oldsmobile made it's own V8 until 1990. The 307, in all it's glory, was available until 1988 in the rear wheel drive Cutlass Supreme as an option.

Pontiac held out until 1982 with it's own V8 which was finally down to a lousy 265 cubic inches and Buick stopped in 1980 with it's own 350 engine.

Sofa is right about the lawsuit. It was for a 1977 Oldsmobile Delta 88 that had a Chevy 350 instead of an Olds. He found out when he went to buy an oil filter for it! The reason as stated by GM is that they were using up every available 350 Oldsmobile engine in their popular Cutlass line. The real reason is that they were re-tooling the Olds 350 to have a lighter casting and they used up part of the tooling on the new 403. Some 350 Oldsmobile (vin code R) engines in 1977 even ended up in a few Firebirds (my best friend had a 77 Formula with an engine vin code R and a numbers matching 350 Olds engine) so nobody really knows where the snafu happenned!

See ya!

80smetalfan

Correct, I was about to point this out.


I've done the opposite of this swap (SBO -> SBC). This kind of a swap is not really too bad in a G-body, as the the 80s G-bodies have bolt holes on the crossmember for both SBC and SBO. Probably not too much fun in a 3rd gen. You'll have to fab motor mounts and find an Olds tranny or adapter plate. If you've got a 700R4 and plan on running an Olds tranny, you'd need a different length driveshaft and may need to modify your trans crossmember (not too hard, just needs a new hole for the mount). Also plan on gaining some weight, SBO has much higher nickel content than SBC. The front of my car even sits higher after the swap because of the weight difference.

As has been stated, I would probably avoid this swap unless you really want the uniqueness of an SBO in a 3rd gen. I'm sure there's an affordable 350 near you somewhere on craigslist.com , if not on our own classifieds.

Sonix

iTrader: (1)

That's freakin' hilarious... Quote of the day!
And so true, late 70's/early '80s Caprices with Olds 307's, and Cutlass' with Chevy 305s. ugh.

80smetalfan

I'd count myself lucky to have a factory 305 Cutlass of that vintage. The 307 sucked bigtime, from a performance viewpoint. Very smooth and reliable though. Just bad on gas and acceleration. Even with the terrible gears and an overdrive tranny, the 307 in my car was EPA rated at 21 mpg highway. My 350/700R4 combo gets 26.

By the same token, I'd hate to have a 307 powered Caprice, lol.

DIGGLER

iTrader: (1)

the 305 was not much if any better than the 307's back then.... so i wouldnt call myself lucky.
i replaced my 260 olds with a rebuilt mild camm'd 350 olds in my '78 cutlass and got the same mileage. lol

KrisW

iTrader: (5)

Ditto that with my '80 Cutlass. I am well into the 20's for mpg with a '73 350 that is basically stock and well tuned. I put an '84 2004R from a Delta 88 and -voila- well into the 20's (best recorded was 25.)

I think the above monte carlo wannabe got much more benefit from the 700R4 than the 350 chevy...

80smetalfan

Apparently you didn't notice that I mentioned having an overdrive tranny BEFORE the swap.

My factory motor had 8.0 to 1 CR, my 350 has over 10.0 to one. That also helps mileage.

As far as the Monte wannabe comment, I simply ran what I had. The swap was easy, and when one compares the aftermarket of an SBC to an SBO, why would you want to go with SBO? Does putting an LS1 in a 3rd gen make them a 4th gen wannabe?

80smetalfan

The 305s in Cutlass's weren't too much better than 307s in factory form, but you have a lot more room to work with a 305 in terms of upgrades. Again, SBC aftermarket is better than SBO.

But this is all a matter of personal preference. I know some guys who would rather build a 403 Olds than any Chevy smallblock. I don't dislike the SBO, they are good motors.

DIGGLER

iTrader: (1)

its all about the coolness with the olds motor. its nice to see a car with something other than the same ol' sbc with run of the mill edelbrock chrome vavlecovers and accel wires under the hood.
fwiw, my 350 olds with the edelbrock performer intake/cam ran 9.0's@78 with a peg leg 3.73 on street tires. better than my '93 z28 ran back when i bought it! lol

KrisW

iTrader: (5)

when one compares the aftermarket of an SBC to an SBO, why would you want to go with SBO?

The Olds engines were all better castings to start with than the cheaper, lighter chevy small block, specifically the engine blocks, heads, cranks, and rods. Less aftermarket money is necessary if you're building a 400 HP engine if you're willing to hit the wrecking yards a little. The stock heads flow MUCH better and have more modification room with valve and port sizes.

Yes, I like the olds engine better. Even a 307 can be made to run well on a budget. Much better than a smogger 305. Keep your shortblock, add some 60's small block cast heads for between 9:1 and 10.25:1 compression. Edelbrock performer RPM manifold (preferably used from ebay) and a hot small block cam will net nice horsepower figures and great driveability without busting the budget. If you want a street machine with better economy then use a plain performer intake (or offy four barrell) and a stock 1969 or 1970 350 ram air cam.

robotic_junky

If you go to Summit Racing, they have an adapter to hooked up a Chevy tranny to a BOP engine. Also I have 1980 Bonneville with an Olds. 350 diesel. You can actually turn the motor into a gasser, if you put in a 427 Olds crank or whatever Olds. big block in the area. Then it will make the engine into a 426 SBO gasser. They used that Olds. diesel until 1985 in all different models.

80smetalfan

SBO doesn't have the $ to HP ratio that SBC has, sorry. Don't take my word for it, there's only like like a half million budget build up articles on the SBC in hot rodding magazines that all basically suggest it's the best budget performance motor ever.

As far whether a 307 can or can't be made to run better than a 305, I'm doubtful that it's really much different than building a 305. You do have a better bore/stroke with a 307 than a 305, and better initial build quality as you pointed out, but that's about it.

mw66nova ran 12.3s with an NA 305 with Vette L98 heads and aftermarket cam/intake, and there are more than a few other cars on here that have got into the 12s and 13s with them. Even if we're going to compare potential using ONLY factory parts off of other factory motors, you still have more options with SBC, even with a 305. Like factory fuel injection, for example.

Why? Chevy has produced more proven performance motors than Oldsmobile. The average build quality of an SBO is higher than an SBC, without a doubt, but Oldsmobile really didn't build as many performance cars or motors as Chevy. It's just a different company.

DIGGLER

iTrader: (1)

how much does it cost to built a 440 cid chevy? (olds 425 crank into 403 block)

80smetalfan

True....

But then again, how much does it cost to modify factory (or aftermarket) Olds heads to enable them to flow as well as AFR heads that are readily available for a 383 or 406 SBC?

KrisW

iTrader: (5)

That's my whole point; you don't HAVE to buy AFR heads for an olds. You do HAVE to buy them for chevy...

Olds made plenty of performance engines and, stock for stock, Olds engines were built MUCH better than chevy engines at the factory. All you have to do is pull apart ANY two engines built respectively and compare tolerances. The truth is that the reason Chevy was chosen by the masses back in the 50's is because they are lightweight and CHEAP. As a matter of fact, they are lightweigt BECAUSE they are CHEAP. The reason the aftermarket favors them is because the public was building the fastest engines in the CHEAPEST way possible. You make more money (if you're racing for money) by following a business approach. The winner gets the same amount of prize money regardless of how much money he invests in his product.

Your dollar to horsepower figure is based on engines making a lot more than 400 HP. For less than 400 HP, you can build them dollar for dollar if you are willing to scour the earth for used olds parts. A set of 455, 425, or 400 heads will make a 350 breathe with much more of a potential than a 350 chevy could dream about. Have you seen the size of the ports and valves? Anyway, you are leaving out the elbow grease factor in non-chevy applications.

Sometimes people like to see what they can do and not just what they can buy...

80smetalfan

It's not like you have to buy AFRs (or even go aftermarket on heads) to make any sort of respectable power with SBC.

There's a science to all of this. There's nothing magical about an SBO, anymore than any other motor.

What CFM do 455 heads flow? Let's see some actual numbers and/or documentation. There's plenty of documented budget builds with SBC that are south of 400 hp using factory heads on this site to compare to. I'm sure Vortec heads will keep up with any Olds casting that would work decently on an Olds 350.

DIGGLER

iTrader: (1)

all i can say is that my 350 olds with tiny performer cam and intake, 9.0:1 compression, holley carb ran dang near what my LT1 camaro did when it had cai and exhaust. basically the same weight cars....