Help with Olds 307 Project

yitzac1990

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Oct 21, 2020
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Huntsville, AL
Hello all! New guy here. I am helping my neighbor with his Oldsmobile 307 engine, to drop into his 1986 Cutlass. I know nothing about olds motors, and very little about classic carb'd motors to begin with. I am an LS guy. I am hoping I can get some help identifying exactly what motor this is, any and all details possible. We are not sure what year the engine is exactly.

What I know:
Olds 307
A4 intake manifold
7A heads
roller lifters

What else it came with:
used Holley 4 barrel carb
350 sbc long tube headers (I think they are SBC 350...honestly my neighbor doesn't know too much about cars, so he just bought whatever)
MSD (I think?) distributor

We ordered the following parts for it....can anyone confirm these will work?


I know I will be switching from roller lifter setup to flat tappet, this should be fine, right? With that cam, is a spring upgrade really needed? or can I keep the stock springs? I will also need to order new push rods, as 4 of them are currently missing, so we ordered some pushrod length checkers as well.

My neighbor is looking for something that'll just sound good, mainly. I am excited to dive into something I have not worked on before, Its always a learning experience.

Thanks in advance for the help!

20201021_112626.jpg
 

Olds 307 and 403

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Oct 4, 2018
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Melville, Saskatchewan
It should be an A5 intake, otherwise there will be a port mismatch. You need a roller cam, flat tappet lifters are smaller than your roller lifters, it won't work. A Vin 9 307 HO roller cam is a good upgrade, you can reuse the factory lifters. You can't use anything Chevy on an Olds V8.
 

yitzac1990

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Oct 21, 2020
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Huntsville, AL
He isn't looking for a stock cam, he wants some lope at idle. All the cams I found for Olds 307 in the aftermarket were flat tappet...any idea where I could find a roller cam?

How bad of a mismatch would the ports be with the A4 manifold? Are the A5's hard to find? I doubt he will want to spend the money on an aftermarket manifold...
 

Rocketman269V

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Feb 26, 2020
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I have a factory A5 intake. Comp Cams has several hydraulic roller cams for the 260-455.
 
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Olds 307 and 403

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He also has a barely 8 to 1 307, the 194/210 .435/.438 Vin 9 cam is nice upgrade, most of the 30 hp gain on the 442 package. Any cam big enough to add some lope and it might not get out of it's own way. A D5 high stall converter, stalled around 2000 rpm behind the 307 HO and 3.73 gears were a big part of the improved performance of H/O and 442. Good luck.
 

yitzac1990

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Oct 21, 2020
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Huntsville, AL
Thanks! I will try to get pics by tomorrow. Also emailed you about the intake.

My neighbor decided to just stick with the cam thats in the motor now. Apparently it has a "nice cam" in it already. Fine by me. We still need some push rods though...does anyone know the oem pushrod length, or have a link to a new set?
 

yitzac1990

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Oct 21, 2020
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Huntsville, AL
I have some pictures here....first the carburetor:

20201026_071927.jpg


20201026_071935.jpg


Then the headers that he bought:

20201026_072013.jpg


20201026_072020.jpg


The distributor is not MSD, I believe he said he wanted an MSD, that is probably what I was thinking of:

20201026_072059.jpg


20201026_072106.jpg


And the distributor base, which is broken:

20201026_072137.jpg


20201026_072144.jpg


Any input on these items is appreciated!
 

Rocketman269V

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Feb 26, 2020
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The Holley carb is generic, will work with any engine; but will need an adapter plate to work with the factory intake. The headers are Olds for sure; don't know what body/engine they're for. The distributor cap is for a stock HEI distributor, again generic. The rotor appears damaged. The distributor is a factory HEI Olds for a computer controlled vehicle (two plugs).
Edit: I just noticed in the image of the distributor, you can see what I was talking about with regard to the intake port mis-matach. Look at the size of the openings in the intake gasket compared to the ports in the heads. :eek: That gasket is for the A4 intake.
 

yitzac1990

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Oct 21, 2020
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Huntsville, AL
i see what you are talking about with the port mismatch, haha!

since the distributor needs replacing, what distributor, cap, and rotor would you suggest be bought for this engine? I am not sure if the vehicle it is going in (1986 Cutlass) has a computer.
 

Olds 307 and 403

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Melville, Saskatchewan
The cheap chinese Ebay distributors are fine, it must be for an Olds V8. Yeah that is a computer controlled distributor, will not give any advance at all. Those headers are the cheap Chinese stainless steel headers from Ebay, they will not fit his 86 Cutlass. They are actually BBO headers but are so affordable and well made, I plan on a set for my 70 Cutlass S. If he can't get rid of them locally, I would be interested if the price is right and willing to ship to Canada. He needs Hedman G body Olds headers for the 260 through 403 Olds V8, part number 58076.
 

Rocketman269V

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Feb 26, 2020
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i see what you are talking about with the port mismatch, haha!

since the distributor needs replacing, what distributor, cap, and rotor would you suggest be bought for this engine? I am not sure if the vehicle it is going in (1986 Cutlass) has a computer.
The cap and rotor are the same, whether computer controlled or not. The '86 came from the factory with a computer unless it was a diesel; however, with the changes that you're contemplating, you want a non-computer controlled distributor. Any early HEI distributor (single 3-wire plug, '75-'80), any size Olds V-8 will work. I have several used early distributors, if interested. I may also have a cheap set of used G-body headers that will work for you.
 

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