I'm having issues with my 69's acceleration/power.
406sbc
600cfm holley
1970 lt1 intake + cam
pertonix ignitor with 1.5ohm flamethrower coil
original distributor.
my current timing is 5* initial with 35* all in
running vacuum advance through manifold
I cant advance my initial anymore without having surging/misfiring at 3,000rpm+
With my initial at 10* it will start to surge/misfire at 3,000rpm.
Could it be fuel pump/filter, both of which have 2,000-3,000 miles on them and are 2 years old
I have linked a video of my current 0-60, it wasnt the best take off but it is the only video i have.
Am I crazy for thinking it should have more power? Is this all the power this motor makes?

https://youtube.com/shorts/cvlOd_X39pE?feature=share

 

You DESPERATELY need to recurve or replace that distributor.
I am running 18 degrees initial, 35 all in at 2,900. with a vacuum advance that adds 12 degrees of timing all in at 12 inches of vacuum and a 800 RPM vacuum of 14.5 inches.
​​​​​You NEED something more like this.
Also your 600 CFM carburetor is Way to small.
If recurving a distributor is beyond your ability.
Contact Davis Unified Ignitions. Order up a custom curved distributor for your engine in your car.
If recurving a distributor is within your abilities, Contact Lars for his timing papers.
And get a much bigger carb.

 

I guess what I am trying to get across to you is this.
Long before you start trying different fuel pumps, different filters, Etc.
Fix what is clearly wrong.
The distributor you have has way to much timing advance to work properly on any performance engine.
Might be just fine for grandma's station wagon.
But WILL NEVER make power on your 406 in its current configuration.
You need to recurve it, have it recurved or just purchase one setup properly for your engine in your car.
You will need to know some details to get it right. Compression ratio? Cam specs and cam timing. Quench?
type of transmission and importantly , your rear gear ratio.
At How many inches of vacuum does your car idle at?
At what vacuum level is your vacuum advance can all in?
How many crank degrees of timing does your vac can put in?
Do you know and understand the 2 inch rule regarding vacuum advance cans?
And if performance is something you would truly like.
A 600 is to small for a 350. Absolute minimum for your 406 should be a 750. But I would think a bit more would be better.

 

i know the 600 is too small. I cant do much about it right now. The distributor that is in the car came from the original 350/350 and the number is 1111493.

 

The surging you described is also known as "trailer hitching". One minute it feels like you are pulling some weight, next minute the trailer is pushing you.
This description is caused by too much vacuum advance. A maximum is around 14, but 10 or 12 is better yet for throttle response, efficient burning of fuel and lower coolant temps, etc.

You have a modified engine. It's time to step up to modified IGN advance. You need an adjustable vacuum advance canister. They usually are preset at half the amount of vacuum adv it can supply. So you may need to bump it up a bit.
You need a advance stop plate added to your current distributor. Summit has them for $15 or so. Both, the plate and the new canister can be swapped out easily, in the car, two screws. The stop or limit plates have four choices / options of max Vac settings. One option is 8*-11* . . . . . .perfect.

Using a vacuum hand pump with gauge, apply vacuum to canister and note how many inches is required to start the adv moving. Inside the vacuum port of the canister is an allen screw. Instructions will advise you how many turns are needed with the allen wrench, to accomplish what you need.

Once the Vac Adv is set perfect your Initial timing will be happier at a higher setting.
So, for a few bucks / hour work, you will have better all-around performance.

 

Will definitely be doing that, thank you.