300/440/550 JS 550 and JS 440 exhaust

[On the fly NY]

morning all...are the exhaust manifolds the same for these?...am in need of an aftermarket used system for some boost to my 550 and seeing some listed as for both while some others are 550 or 440 specific ...some help clarifying would be greatly appreciated...thanks

 

[Big Kahuna]

The 550 used the JetPower "Breadbox" design from 1985/1986 on, the 440 had a different design, early 550's were similar. The Breadbox exhaust is actually pretty good, only exhaust that gave any real gains was the Factory Pipe Half Pipe design. A full exhaust system only really worked if you ported the cylinders.

 

[On the fly NY]

tnx BK...since I have the whole engine apart, I will be porting the cylinders...would like to get the most out of her without going too crazy or falling too deep down the rabbit hole

 

[fastgtfairlane]

I have a jetsport exhaust manifold id let go of if youre interested. Its for a full pipe.

 

[On the fly NY]

I have a jetsport exhaust manifold id let go of if youre interested. Its for a full pipe.

possibly...how much and where is it located?...any pics?...tnx

 

[fastgtfairlane]

Ill send a pm.