H.O. Swirl Port Oldsmobile 307 parts?

kustomkyle

G-Body Guru

Apr 14, 2008

646

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• Nov 8, 2008

• #1

I was looking around to see what components are needed to make a VIN Y swirl port (1986+) Olds 307 into the high output version. I found a list but does anyone know if there is more or if the list is wrong? I don't know if the list is for the earlier engines or not, which would definitely make a big difference.

"Long Duration cam shaft 22519934
High Rate Valve springs 22510372
Harmonic Balancer 417142
Rochester 4MV carb 17083553
Dual Snorkel Air Cleaner Assy. 25042690
Intermediate Exhaust Pipe 22516113
Muffler and Tailpipe Right 22526204
Muffler and Tailpipe Left 22526205
2400 RPM locking stall converter ?? "

I looked up the valvespring part number given, but it comes up as a number for a V-6 component. Is that correct for some reason? Any help would be appreciated.

 

Blake442

Geezer

Apr 24, 2007

6,871

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Minneapolis

www.cardomain.com

• Nov 8, 2008

• #2

The H.O. motors also had an aluminum intake manifold.

You should ditch the 7A heads in favor of the 5A ones.
The 7A's cut the hp down a tad from the previous 5A's that they replaced.

I have both of those things if you're interested in them. I also have a carb.

 

beeterolds

Master Mechanic

Dec 15, 2007

438

3

18

Cleveland ohio 44131

• Nov 8, 2008

• #3

The 5A heads are better for a few reasons.. A.) they have larger 350 size ports B.) they will respond nicely to porting/larger valves etc.. The 7As were meant for mileage and low rpm performance.. the 307 was basically a gasoline burning low compression diesel engine!! it was slow as balls but sure could pull a house down at low rpms.

 

kustomkyle

G-Body Guru

Apr 14, 2008

646

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• Nov 8, 2008

• #4

Aren't the earlier 5A heads non-interchangable with the newer 307's? I thought the 86"+ ones had the same heads between the VIN Y and VIN 9, or is there a newer version of the 7A that goes with the newer engine design?

I'm kind of confused. What I was thinking of doing was getting my 1986 VIN Y 307 rebuilt but add the H.O. components that go with the later engines. Yeah, you could get more power with a bigger engine, but that isn't what I want to do. Emissions, gas mileage, etc. are all a concern.

 

Blake442

Geezer

Apr 24, 2007

6,871

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Minneapolis

www.cardomain.com

• Nov 8, 2008

• #5

Both the vin Y and 9 used the same heads depending when they were built. The 5A heads are most definately interchangeable.

About half-way through the '85 model year, they switched from the 5A to the 7A, and the change was responsible for a 10 hp loss. The short blocks are all the same, and a "newer" 307 doesn't exist.

That's why your '86 has 7A's, and my early '85 442 had 5A's. The '86 and '87 442's will have the same 7A's that you have.

You could leave your heads on and still add the cam, intake, carb, etc. and technically be a 'correct' vin 9 style build, but switching the heads might be a good idea. Helping an Olds motor breathe better will wake up the performance considerably.

 

D

dan2286

Royal Smart Person

Mar 25, 2008

2,233

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38

Cleveland, Ohio

• Nov 8, 2008

• #6

Dont the newer engines use a roller cam setup?

 

kustomkyle

G-Body Guru

Apr 14, 2008

646

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• Nov 8, 2008

• #7

dan2286 said:

Dont the newer engines use a roller cam setup?

Click to expand...

That was what I thought. I would imagine the valvetrain and other parts are completely different in the roller cammed engines. I don't know?

 

kustomkyle

G-Body Guru

Apr 14, 2008

646

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• Nov 9, 2008

• #8

I guess a better question is what has to be changed if I put the 85"- 5A heads on a 86"+ engine?

 

megaladon6

Comic Book Super Hero

May 29, 2006

4,005

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0

Danbury, CT

• Nov 9, 2008

• #9

with a roller cam you only need the right lifters and the thrust button in the timing cover. the heads don't really matter. well, as long as the springs have the right lift capabilities.

 

kustomkyle

G-Body Guru

Apr 14, 2008

646

47

28

• Nov 9, 2008

• #10

Changing heads might be a little much for what I want to do, but I'll consider anything if I can get the right parts for a good price. I was thinking changing the cam and valvetrain components wouldn't be a big deal because in a rebuild they might need to be replaced anyway.

My biggest concern is finding the correct/new parts. Should dealers still have H.O. parts like camshafts? Does anyone have a definite list for the 86'-87' 442 or VIN 9 engine and/or part numbers?

Also, what significance does the aluminum intake manifold have over the regular one? Do they differenciate by year?