Stock 442 Exhaust

[Texas82GP]

Get this.
https://m.summitracing.com/parts/sum-680146-nm
These unfortunately work only with early manifolds. They changed from a 2 to 3 bolt flange and the angle on the passenger side is different. The driver's side should bolt right up. I forgot about the manifold change.
https://m.summitracing.com/parts/pye-dof10s
Here is the cap but headers will be easier.
https://www.yearone.com/Product/1964-72-cutlass-442/bfp70
This muffler.
https://m.summitracing.com/parts/hok-21504hkr
Use these over the Flowtech which rust and many have fitment issues. Some tweaking of the pipes may be necessary to hook it all up.
https://m.summitracing.com/parts/hed-58070/applications?prefilter=1
The H pipe is cheaper, I have used this kit before.
https://m.summitracing.com/parts/sum-642025
Of course a dual hump cross member is still needed.
I used this system on my 88 Cutlass Supreme, runs under the stock crossmember, fits nice and uses a different catalytic converter but comes with a bolt up elimination pipe. A custom dual set up is another option.
https://m.summitracing.com/parts/hok-16810hkr

You might hate SBC's but you are there for the Olds guys. It was nice of you to put in that level of effort to help a fellow member.

 

[olds307 and 403]

Running the Olds V8 isn't always plug and play, especially modifying them. Another option is the Hurst/Olds 442 Cat back dual exhaust, basically factory replacement. The parts are still available, I believe. Your early 307 will perform better with less corked exhaust. Even on the mighty 8 to 1 Olds 350's with #8 heads, the dual exhaust option was worth 20 HP and 25 ft/lbs of torque.

 

[Andebe]

Is there a Kit for the X pipes Jegs?Summit?

Does the Pope wear a funny hat? 😉

 

[MrSony]

This place sells new manifolds for 300 bucks that don't have that stupid cross over passage. http://thorntonmusclecars.com/product/thorntons-350-jr-exhaust-manifolds
Other than that, just a block off plate and what others have suggested would be your best bet.

 

[Young0utlaw81Cutlass]

Does the Pope wear a funny hat? 😉

I'm not sure...J/K

 

[Young0utlaw81Cutlass]

This place sells new manifolds for 300 bucks that don't have that stupid cross over passage. http://thorntonmusclecars.com/product/thorntons-350-jr-exhaust-manifolds
Other than that, just a block off plate and what others have suggested would be your best bet.

Do i need both or just one side passenger? Or Blocking the plate would alot less cause i still need buy the mufflers.

 

[Texas82GP]

Do i need both or just one side passenger? Or Blocking the plate would alot less cause i still need buy the mufflers.

Those are better performing manifolds but for a cruiser, you would be fine with just blocking off the extra port on the passenger side manifold and dualing the system out.

 

[Young0utlaw81Cutlass]

Get this.
https://m.summitracing.com/parts/sum-680146-nm
These unfortunately work only with early manifolds. They changed from a 2 to 3 bolt flange and the angle on the passenger side is different. The driver's side should bolt right up. I forgot about the manifold change.
https://m.summitracing.com/parts/pye-dof10s
Here is the cap but headers will be easier.
https://www.yearone.com/Product/1964-72-cutlass-442/bfp70
This muffler.
https://m.summitracing.com/parts/hok-21504hkr
Use these over the Flowtech which rust and many have fitment issues. Some tweaking of the pipes may be necessary to hook it all up.
https://m.summitracing.com/parts/hed-58070/applications?prefilter=1
The H pipe is cheaper, I have used this kit before.
https://m.summitracing.com/parts/sum-642025
Of course a dual hump cross member is still needed.
I used this system on my 88 Cutlass Supreme, runs under the stock crossmember, fits nice and uses a different catalytic converter but comes with a bolt up elimination pipe. A custom dual set up is another option.
https://m.summitracing.com/parts/hok-16810hkr

The Hooker Chambers sound's good.

 

[Young0utlaw81Cutlass]

Those are better performing manifolds but for a cruiser, you would be fine with just blocking off the extra port on the passenger side manifold and dualing the system out.

Yes this is what i want to do but Thanks guys for your info.

 

[olds307 and 403]

My car with Sanderson shorty headers, 2.5" dual exhaust, compact X pipe with Hooker Areochamber exhaust.

The Thornton manifolds are anyone guess how much better than stock, probably single digit numbers. Even the better W30 manifolds give up 30+ HP and TQ. Olds wide block leaves little room for manifolds to fit.