Olds 307 Exhaust question

After climbing under my 88 Cutlass I have to say the stock exhaust is about the most restrictive thing I've seen lately....the drivers side manifold pipe is rounted INTO the front of the passenger side exhaust manifold?? And then a single pipe comes out of the rear of the passenger manifold to the actual exhaust. No wonder the poor car can't breathe!

I don't remember my 89 Custom Cruiser 307 having this setup, but it may have....

So anyone have a suggestion for replacement manfolds? Can I just use the stock single-outlet driver's side manifold and replace the two-opening passenger side manifold with something from an older Olds V8? I want to dual the car out shortly, but don't want to attack it until I replace the manifolds...and I don't want to use headers, prefer stock manifolds. Will older Olds 350-403 manifolds bolt on....or do they have this "wrap-around" design too?

I can't imagine I'm the first person that has tackled this issue. Advice is welcome!

-Mike

did you ask the G body forum yet?

I did but no replys yet. I'm planning to hollow out the cat converter once I get the car back from my mechanic friend. I think the converter may be clogged. Want to do duals soon, as money allows.

Also need to find what rear axle would be a bolt-in, and start looking in the yards. It has 2.43's in it now. Stupid! Think that would be an easy weekend project, and at least the 15-year-old Honda Civics will no longer be able to beat me off the line.

-Mike

who is troy thorton?

seems most just go with headers, if I were you take a walk through your local yards and see what the boxy wagons had on the passenger side for manifolds

the 307 has been around for a while so you never know what you might find

10-4 and thanks. I'd planned to go yarding yesterday but it was cold and raining. Maybe next weekend.

The 307 Y motors all had that goofy set up no matter what they put it in. A friend of mine ran into this problem about 15 years ago with his '84 Cutlass 403ci. swap. Olds used that inlet/outlet right side manifold as far back as the mid seventies from what we found going through the junk yards back then looking for standard looking manifolds. Long story short, he ended up going with headers, and a G-Force double hump trans cross member with Torque Tech 2 1/2" exhaust with Flowmaster 40's, sounded mean.

As for the rear axle, look for a G body 442/Hurst Olds, Buick GN/T Type, Monte Carlo SS, or even a Pontiac GP 2+2. All had the 8.5" 10 bolt, and most had 3.42's with a limited slip I think. The LSD is probably trash by now, but they do pop up on CL , and/or eBay that have been recently gone through quite offten. If the sky's the limit, Strange, Mark Williams, and Mosher make 9" Ford rear axle bolt ins, and one of them makes a GM 12 bolt that also bolts in.

Mike

http://dallas.craigslist.org/dal/pts/2163554150.html

http://dallas.craigslist.org/ndf/pts/2177341013.html

Sounds like you should call this seller, he may know about the manifolds if not have them.
http://dallas.craigslist.org/dal/pts/2163542008.html

Man, you have a lot of good stuff down there in Texas! CL is full of older Olds stuff!

Ha, Athens. That's about as country as you can get, but I will call the guy. Thanks for all the tips and links.

What river did they pull that poor 442 out of by the way.....?

with how old this thread is not sure if there's even any reason to posting this but who knows.

My 87 Pontiac has a 307 in it and while the driver side exhaust does go over to the passenger side manifold it does at the rear of the manifold then goes out towards the rear. But the manifolds themselves are steel, not cast iron, so I don't think it would be too hard to modify a stock manifold to allow for proper dual exhaust by cutting out the part for the drivers side pipe and then welding a new flange on, or just block off the mounting flange for the drivers side cross over.

You can certainly do the custom fabrication you describe , however, it is a labor of love. Even after you do all that you might get 15 HP out of it.

I think the most value is from swapping in a regular OLDs 350 motor such as a 1968-1972 and then do duals or headers on that. At that point you will be about 100 HP ahead in round numbers and you can still do additional items on a 350 that the 307 cannot do. The 307 is a great motor for regular use below 70 MPH. Typically when you try to get more out of them you will be sad. That are just a good reliable motor for around town use. They do not like mountains and hills and they do not race very well.
I had one in my 1982 Olds Delta 88 and it was just a good all around motor. My engine had full dual exhaust with no Catalytics, and just two turbo mufflers. It sounded awesome and turned a lot of heads since people saw the big long car and assumed it was a 455. But no. Just a little 307!

I had a similar exhaust on my 66 cutlass 330. I removed the crossover and had a small section of the old crossover pipe welded closed and blocked the crossover port with that. Then I ran the optional dual exhaust system from the stock manifolds.

At the risk of awakening a very old thread, I need to add my latest efforts. I cracked a head on mu 1989 lesabre estate wagon, 307 olds

I found a head and sent it out to a local machine shop to be touched up. At some point, the stock exhuast manifolds became unuseable. (don't ask) A previous owner had cut and plugged one outlet on the passenger side and installed tru duals. great sound good flow, just bitchin...

When the stock manifolds were no longer useable, I thought to replace them with a shorty tube header, simple, right ?

Not so fast Rickey Racer, after arresting all the usual suspects, (headman, Dough Thorley,Holley, pertronix, et al)The only supplier that said they could help was Mondello. They offered a mid length, cerma coated, 1 3/4 inch tube dia. piece of jewerlery,     (Part # JM-8489-307) $549.00/set bolts and gaskets extra)

That figure is way out of my budget, I just dropped $2600.00 on the engine. What I need to find now is a pair of used stock manifolds. I'm told that any small block, cross over, style will work. Those from any olds small block 350-307 will work. even the non cross over style will be an easy hook up to what I have now.

It took me nearly 2 weeks to gather that info. Can any body out there help me with this? (At this point, I'm looking for that old rusty pair, layin in the dirt behind the shed.........HELP

Thanks,
Paul in da swamp

Give this a try

www.car-part.com

Oldsmobile was pretty ubiquitous with all their stuff - 307-455 (including 350 diesel) all more/less interchange.

https://www.car-part.com/cgi-bin/search.cgi?userSearch=int&userPID=1000&userLocation=All+States&userIMS=&userInterchange=E%3FF&userSide=&userDate=1983&userDate2=1983&dbModel=12.5.1.1&userModel=Buick%20Regal&dbPart=327.1&userPart=Exhaust%20Manifold&sessionID=13000000087040897&sURL=www.car-part.com&userPreference=price&userZip=12345&userLat=42.8145000&userLong=-73.9403000&userIntSelect=2026219&userUID=0&userBroker=&userPage=1&iKey=

Personally, I wouldn't bother with stock, I'd put the money towards these!

https://www.ebay.com/itm/1964-1988-OLDS-442-CUTLASS-350-307-330-SMALL-BLOCK-DUAL-EXHAUST-MANIFOLD-HEADER/382891506678?hash=item59261cbbf6:g:SK4AAOSwXFRcRhmN

I found a set of "high performance cast iron headers" from an outfit in Georgia. True duels, no crossover. $175.00 $42.00 shipping. Gonna call and order in the morning. YEEEEEEE Hawwwwwe.

Paul

Well, that was a bust, bait and switch, $175.00 for one side only, plus big shipping. back to the web, I guess.

Paul

I have 86 olds 442 cast iron manifolds if you are still looking.not sure they fit a wagon though.

Thanks for the response, I've been running down all the yards listed in the Car-parts link, Many have one or the other, not both.

Most will not quote shipping, other than to say: buy it and we will ship it for cost (actual shipping?) I sent the last batch the VIN as well, those that answered my request wanted a VIN for a final check. I was not aware that most yards even did VIN cross checks on small parts.

If I get a good response, I'll have them cross check to see if yours will fit. I'd rather buy from another board member instead of a yard half way across the country.

Again, Thanks

If you are near 11378 you can also pick them up..im looking for 80 bux for the pair