Olds 350 Swap

[Nate88]

Hi everyone i'm new to the forums and this is my first post. I have an 81 C10 with an Olds 350 engine. I didn't see a recent post about this engine swap. So i figured i would write a post about it. I have owned my truck since 2016 and in that time i have become extremely familiar with the Oldsmobile V8 engine family. My tuck was actually built with the Oldsmobile 350 diesel engine. When it died like many of them did a Olds 350 gas engine was installed in its place. I decided to buy my C10 after i lost my 94 Ram 1500 to an unfortunate roll over accident. I have a 1969 cutlass project car that i have been accumulating parts for over several years. So i decided to buy the C10 so i could use some of the extra parts to get them out of my way...lol

But back to the Olds 350. The 350 Olds actually makes for a very good truck engine. They have some unique design characteristics that's favorable for truck use. I will give a detailed description and explanation about those features. Im going to break this up into a series of post's. There's a ton of information that i can share about this engine. So i would like to share it to anyone thats interested. I will also add photos when i get the time.

 

[Nate88]

First off some basic specifications of the Olds 350

Deck Hight = 9.33 Inches
Bore Spacing = 4.62 Inches
Bore Size = 4.057 Inches
Stroke = 3.385 Inches
Rod Length = 6.0 Inches
Main Bearing Diameter = 2.5 Inches
Rod Bearing Diameter = 2.125 Inches

 

[Rusty Nail]

Hi everyone i'm new to the forums and this is my first post. I have an 81 C10 with an Olds 350 engine. I didn't see a recent post about this engine swap. So i figured i would write a post about it. I have owned my truck since 2016 and in that time i have become extremely familiar with the Oldsmobile V8 engine family. My tuck was actually built with the Oldsmobile 350 diesel engine. When it died like many of them did a Olds 350 gas engine was installed in its place. I decided to buy my C10 after i lost my 94 Ram 1500 to an unfortunate roll over accident. I have a 1969 cutlass project car that i have been accumulating parts for over several years. So i decided to buy the C10 so i could use some of the extra parts to get them out of my way...lol

But back to the O

Hi everyone i'm new to the forums
I have a project car that i have been accumulating parts for over several years....
So i decided to buy the *blank* so i could use some of the extra parts to get them out of my way...lol


I will also add photos when i get the time.

why does that all sound so familiar? Who T F is this guy?



oh yeah. We're in the same club!


Tell us who ya are and how ya did it! Didja have the coffee?


wait...




P.S. it's super easy to add pix from your phone- only takes a second.

 

[Nate88]

Now to some of the design charaterisitics that make the Old 350 a good truck engine.

The first thing that i love about the Oldsmobile V8 is the fact that the Distributor does not pass through the intake manifold. So you do not have to pull the distributor to change intake's. This is especially nice if for some reason you develop an intake gasket leak. You simply replace the gaskets and be done with it. No need to restab the distributor or adjust and play with the timing.

Second the spark plug's are above the exhaust manifolds and are extreamly easy to replace. Also no need to worry about running short header style spark plugs. And no need to worry about your spark plug wires touching hot headers.

Third the fuel pump is attached with 1 bolt and 1 stud & nut. The Olds V8 uses an offset fuel pump essentric that's attached to the camshaft bolt. So no silly fuel pump pushrod to mess with if you need to change one out.

Fourth there are NO core/freeze plugs on the backside or on the front of the engine block. They have 10 total with five to a side and none of them are behind a motor mount. This is nice if one rusts or blows out for some reason while your hauling or towing something you can easliy install a temproray rubber plug and be on your way.

Fifth none of the headbolts screw into a water jacket and don't require any kind of sealer. There are only 4 bolts on the Olds V8 that require sealer of anykind the 2 bolts that hold on the thermosat housing. And the two small water pump bolts that screw into the timing cover. And they only require a little dab of RTV.

Sixth The Olds V8 has better gasket sealing in general compaired to the pre 1986 chevy small block the newer 1987-95 small block does beat out the Olds V8 though by virtue of the the 1 pc rear main seal and the center bolt valve cover design. The Olds V8 uses an old style rope rear main seal from the factory. There are modern neoprene seals available that can installed upon rebuild. The Olds uses the perimeter bolt style for the valve covers with 10 bolts vs 4 as compaired to the SBC. They also have machined valve cover rails from the factory and can utilze reusable valve cover gaskets.

Seventh The Olds V8 uses a thermostat bypass tube. On the thermosat housing and water pump that allows coolant to flow throughout the cooling system even while the thermostat is closed. This allows the entire cooling system to warm up evenly.

Eighth The Olds 350 is actually easier to retrofit to use a roller style camshaft than pre-1987 SBC's. This is possible because you can install the factory camshaft retainer plate from the 1985-90 Oldsmobile 307 engine. This piece litterally just bolts right onto the block. The 307s also had a cam button attached to a spring that slide's onto the camshaft bolt that control's camshaft walk. So no need to measure camshaft end play. And recently affordable roller lifters have been made available for the Olds V8 they run around $300 for good american made lifters or cheap china lifters for $120.

Ninth The both Oldsmobile Small & Big Block's use the same timing cover's, Valve covers, Oilpans, timing chains, camshafts, fuel pumps, distributors, rocker arms, assessories and pullies. So you can reuse just about everything you bought for one on the other. Its even possible to use big block oldsmobile heads on a small block oldsmobile engine. You have to use a edelbrock performer rpm intake and port match it to the heads. since the big block heads have much larger intake ports.

Tenth The Olds V8 is doesn't require machining to use screw in studs and guide plates for the valve train. There are special stud's from ARP that you can buy that will thread into the rather small 5/16 bolt thread size thats on the heads. And use i think a 3/8 stud size for the rocker pivot. The kit installed onto my engine used this setup which allowed me to install 1.6 ratio small block ford roller rockers.

Well i hope all of this was somewhat helpful and an entertaining read.

 

[Nate88]

Haha nope I'm not a member of any truck clubs....lol

 

[Nate88]

heres the list for whats needed to install an Olds V8 in a Chevy or GMC truck.

1.) Motor Mounts- Original frame mounts for the Olds diesel like my truck has are pretty hard to find. With the factory frame mounts you can use standard rubber engine mounts for an oldsmobile engine. The factory frame mount is all metal with the rubber mount bolting to the side of the block. Like this

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[Nate88]

stock chevy mounts look alot like this.

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[Nate88]

The solution is to either fabricate your own mounts or buy 403 mounts from a 77-79 Trans Am. They will pretty much allow you to install an Olds V8 into anything that uses standard chevy style frame mounts. They look like this.

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[Nate88]

2.) Either a BOP th350/400 transmission or a transmission adapter kit. https://www.summitracing.com/parts/pma-pa99614

 

[Nate88]

The rest is simple wiring and hoses for the exhaust its pretty simple also. Run either factory Oldsmobile exhaust manifolds or Headers. I used cheap ebay stainless steel headers for a 68-72 cutlass. They do come extreamly close to my front lower control arms but don't touch. There is a company called thorton that sells factory styled shorty headers that are supposed to be basically a bolt on replacement to factory manifolds also. Yep thats pretty much all ya need....lol

 

[Camar068]

https://www.hotrod.com/articles/wise-performance-engineering-465ci-oldsmobile-engine/

 

[Nate88]

Here are some pictures of the 68-72 cutlass headers installed on my truck.

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[Memaloose]

Good info to file.