Backfire

[Zukeman]

Hi. I have an automatic 77 K10 with stock 350 and Edlebrock. Truck is up and running after sitting for a few months.
It has a new fuel tank, fuel, fuel filter. Truck now backfires when slowing down. I hit like 65 mph, took foot off gas and several small pops from exhaust. Any ideas to try first ?

 

[Vbb199]

Sparkplugs

 

[fast 99]

Exhaust leak will allow O2 to enter under decel.

 

[Zukeman]

I ran it today and I can hear a leak at driver exhaust manifold. Thank you..mike

 

[fast 99]

Take it off, get it sanded flat reinstall using high temp silicone. DO NOT USE GASKETS.

Most of those manifolds do not have the cast in tie bar. If yours doesn't get a set of spreader tools to line up the bolts. Even then you may have to enlarge the holes. Or optional, get a new manifold.

 

[WP29P4A]

@fast 99 After working on all kinds of vehicles for over 46 years I'm a little embarrassed to ask, but, What is a "cast in tie bar"? What are you spreading with the "spreader tools"?

I fully understand the "enlarge the holes" been there done that several times.

 

[fast 99]

Top is with bottom without.

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[fast 99]

spreader, goes in between openings of manifold. It's right and left threaded. Only for installation, remove after tightening bolts. Need 2.

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[Radiohead]

And don't be meat headed about it. Get too happy with it and dink. It usually takes just past a little rch to get it to fit right.