A "slightly different" exhaust manifold question?
 

1988 C2500 5.7...... I just replaced both exhaust flange doughnuts, due to a leak. Nuts..... there is still a leak ( it must be near the flange)....

If I replace a stock manifold, & maybe replace both, I want everything to bolt up & fit emissions the same. Is there such thing as a better version of a stock manifold? Maybe flows kind of like a header, or just "massaged" inside the manifold? No headers, unless they fit as stock, considering spark plugs, smog, etc... ( I read the issues of header fitment problems)

If not, I'll just do OEM.... But I thought I'd ask you guys first.

Re: A "slightly different" exhaust manifold question?
 

Check out Dorman 674-530 and 674-531. They are a copy of a factory tubular manifold on late '80s trucks and do have ports for AIR injection.

https://images-na.ssl-images-amazon....L._SL1500_.jpg

Re: A "slightly different" exhaust manifold question?
 

Thanks... I'll check it out...

( It is made in China)..... But I'll check!

Re: A "slightly different" exhaust manifold question?
 

Might as well run headers....those are the same style steel with flange vs the oem cast iron that doesn't warp.
As for something different- nobody makes one that I'm aware of because if people are going to spend full aftermarket part price for something they want aftermarket performance from it not just slightly more then stock, at least that's how I see it.

Re: A "slightly different" exhaust manifold question?
 

Fixed the exhaust leak..... Loose hose clamp on a rubber hose connecting the AIR INJECTION PIPE, at the lower/rear passenger side, just as it runs around the rear of engine.. .....nice....

I'm leaving everything alone..... time for a new muffler....