Proper timing for 454 BBC?

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AyWoSch Motors

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Hello there.
I have a 454 big block with a few modifications in my 75 K5 and was wondering what proper timing should be.
It's a 74 block out of I believe an old impala wagon. It was rebuilt in the mid 90s, but no major performance parts were added.
I bought it last year, and right now it has open long tube headers, a carter 850cfm performance carb, on a half inch open carb spacer, and every accessory taken of the engine, except the alternator.
It has brand new air filter, new plugs, new plug wires, mechanical choke cable, and runs on normal pump gas.
When I first got it, it was so far out of time it would barely run except to rev it out, right now I have to set to between 12 and 14 btdc.
It starts right up, and runs well, but when your driving it and get it up above about 3500 or 4k sometimes it will pop and sputter and bog, and lunges a bit like I have the choke on full, but it isn't.
Please help.
 

AyWoSch Motors

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As you can see, its garbage, but I want it to be good running garbage.
I'm going for a mad max/rat rod/mud truck sorta thing.
 
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bucket

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Your timing is ballpark for what the average engine will like. You may have a fueling issue.
 
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Yeah, sounds like it's starvin for fuel.
 

AyWoSch Motors

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It shouldn't be starving for fuel, its sucking off the original tank, which I just cleaned.
Stock type Chevy mechanical pump, stock type 3/8 ID gas line, brand new filter, ect.
 

bucket

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It shouldn't be starving for fuel, its sucking off the original tank, which I just cleaned.
Stock type Chevy mechanical pump, stock type 3/8 ID gas line, brand new filter, ect.

Check the fuel pressure between the pump and carb. Should be 5-7 psi. If that checks out then the carb needs looked at. It could be something as simple as the float level is set too low. Or possibly there's crud blocking a passageway somewhere. Is the carb an actual Carter, or the very similar Edelbrock?

It's also still a good idea to check out the condition and functionality of the distributor too.
 

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I always go to timing first then to fuel
 

AyWoSch Motors

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Check the fuel pressure between the pump and carb. Should be 5-7 psi. If that checks out then the carb needs looked at. It could be something as simple as the float level is set too low. Or possibly there's crud blocking a passageway somewhere. Is the carb an actual Carter, or the very similar Edelbrock?

It's also still a good idea to check out the condition and functionality of the distributor too.

It's an actual Carter Pro Carb.
I don't have a fuel pressure tester, so I'll have to get one. I'll look into cleaning the carb too, thanks.
The Distributor is a regular vacuum advance HEI, not sure how to test that without just buying a new cap.
 

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Any update on this?
 

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I'd set your timing with a vacuum gauge. See what it likes. Adjust timing for maximum vacuum and then back it off a few degrees.
 

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Some timing lights will show the advance on the screen, too.
 

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To your original question with the engine specs you stated, The BBC would do well with A total advance of 36 degrees, and an initial of around 8. Higher octane would allow you to bump the numbers up. You didn’t mention the distributor you are running, I suspect an HEI.

I agree with earlier posts and think it is a fuel issue. Best wishes.

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AyWoSch Motors

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Any update on this?
So, as I'm sure happens to everyone, life got a bit busy, but I have done some basic tinkering with it.
I changed the fuel filter, and blew out the lines with an air tank, to go off the idea of fuel issues. I redid some questionable wiring. And I did some more tuning to the timing. I timed it, took it for a ride, timed it took it for a ride, and so on and so on.
Right now its set at about 18btdc at idle, which seemed a little high to me for idle, but it seems to like it, idles smooth. At wide open it doesn't sputter or bog, it rips better than ever.
It was running so smooth the other day I took it all the way down my road, shifted through all 4 gears with only the power of idle, didn't touch the gas once.

My biggest problem I realized, is that I was being a moron. March at my house is cold, and I'm running open long tube headers. Total duh moment, missed the obvious.
Now that its warming up, its running better.
Still backfires every now and then, and you think someone is shooting at you, but that's because the carb is running a bit rich. Which I dont really care about. It's not like it's a daily, I just like bringing friends out for a ride to scare the hell out of them.
The only person I cant scare with that thing is my 76 year old grandpa. Tough little Vietnam Vet isn't even fazed by that thing, haha.
Thank you all for your suggestions and help.
 

AyWoSch Motors

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Recently painted on some SS decals. That added atleast 10 mph right there, hahaha. Came out pretty good for doing it free hand with a roll of tape and a box cutter.
Also painted the tips of the fan blades just for fun.
Kinda looks like a plane propeller, and it helps to not cut your fingers off when your timing it while running.
 

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