87 Jimmy Exhaust in cab Fix
 

True duals. Noisy and leaking.

No smell windows up. Lotsa stink any one window cracked.

First I fixed the leaks with new manifold doughnuts.

Still stinks.

Second I added a stick on foam weather strip to the tailgate.

Still stinks.

Finally-noted the black stain on the inside of the rear bumper. Tail pipes effectively dumping under the truck in the vacuum. Window open and it all got sucked in back to front.

Extended both pipes out the sides just shy of a plane even with the edges of the bumper and problem solved!

How nice it is to take a ride with the windows open and not have watery eyes and a headache!

Re: 87 Jimmy Exhaust in cab Fix
 

That large, flat ass end makes for a huge low pressure area that will suck exhaust gasses in if they're not dumped in the breeze the way GM did stock. Even still, you'll get on occasional whiff if you do a lot of riding with the top on and back window down.