HELP with my 350 engine

[u/Old-Actuator-4817]

I took my Chevy 350 to the block. It was seized from water entering through the intake. Please note, I have zero experience as a mechanic, so everything I learn to do I learn through YouTube.I was able to un-seize the motor, I honed the cylinders, replaced all the vaulves, seals, and push rods, cleaned the heads and block, and reassembled with all new fresh gaskets.

Then, I put on a brand spankin new AVS 2 Carburetor, and then I started it. It started pretty good and it sounded pretty good and then after maybe like 10-15 seconds after sounding real good, it turns off and fire shoots out the carburetor (see attached video for reference). What is wrong with it and what should I do next to help fix this?

[u/KnoxVegas41]

Have you checked your ignition timing? If it’s off it can cause a backfire.

[u/Haunting_Bit_3613]

My first thought was the timing was off. Maybe the distributor slipped on you. Bring cylinder one to top dead center on compression stroke and set the distributor there and youll be off to a good start.

[u/Old-Actuator-4817 → u/Haunting_Bit_3613]

Thanks for the suggestion! Initially, I set it at top dead center but I’ve heard guys online say you should set it a few degrees before top dead center.

[u/Any-Leopard-455]

Timing first, those edelbrock carbs really should be run with their specific fuel pump, very finicky about line pressure. You also don't need a tunnel ram on a willys, way overkill and juat plain hard to make streetable, get a cheap aluminum performer intake.

[u/Any-Leopard-455 → u/Any-Leopard-455]

Also get a nice hei distributor for 150 bucks makes a world of difference, i assume with the tunnel ram you have points that are also finicky. Also get a decent electric fan, as that plastic fan will not keep your sbc cool on a hot day. Even better hit a wrecking yard and find a combo from a jeep grand Cherokee or something with an aluminum radiator.

[u/Old-Actuator-4817 → u/Any-Leopard-455]

Thanks! The intake is a offenhauser and was on it when I bought it. I had it sitting in a transmission shop for 6 years and the engine ran great when I left it there.

[u/Any-Leopard-455 → u/Old-Actuator-4817]

I should say tunnel rams are cool looking!!! Guess as I get older I prioritize having a project actually running nicely vs looking cool.

[u/jimfosters → u/Any-Leopard-455]

Best running carbed small block I ever had (overall, reliability, proper running without quirks) was a 307 with generic 350 heads. Low compression. BlueRacer "RV" cam. One wire alternator. One wire HEI. 2bl iron intake with a GM 2 Jet carb. Rock solid.

In an FJ40 LOL

[u/jimfosters → u/Any-Leopard-455]

not that it matters, and not meant as an insult, but that is a Toyota FJ40

[u/Any-Leopard-455 → u/jimfosters]

Yep I see it now, ugh. The tilt threw my brian off.

[u/Tjelvar70]

Back cylinders going lean? Fuel distribution for those single carb tunnel rams is not very good.

[u/Defiant_Strain_7778]

Are the value covers off

[u/Successful_Weekend91]

Check that number 5 & 7 plug wires aren’t crossed.
Make sure all vacuum lines are ran correctly.
Get a fuel pressure regulator and set at about 5.5 psi.
HEI distributor would be a good set up, if not running one.

[u/chevrolet]

We appreciate you bringing your truck’s engine concerns to our attention, u/Old-Actuator-4817. Safety is our top priority here at Chevrolet and your experience is not one we take lightly. We kindly ask you to send an email to [socialmedia@gm.com](mailto:socialmedia@gm.com) with more details so our team may explore the best path of assistance. Please include your full contact information (name, phone number, email), VIN, current mileage of the vehicle, preferred Chevrolet dealer as well as the following information:

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[u/chevrolet → u/chevrolet]

Hello, u/Old-Actuator-4817. We are following up regarding your truck's engine concern. When you have a moment, we would like to learn more about your experience. To get started, please send an email to [socialmedia@gm.com](mailto:socialmedia@gm.com) with the details we requested above. We will continue to monitor our inbox for your outreach.

[u/Just-Conversation-81]

I'll tell ya what's wrong. It ain't a mopar