76 corvette ,350 popping thru carb at w.o.t

I've been tweaking my 350 for about a month.
Here's the history: has edelbrock 1406 4 barrel carb, I installed new aluminum intake, new plugs and wires, new cap,rotor,coil.
I rechecked timing and set it to factory specs. I have played with the timing
but it has no effect on this problem. My last attempt to solve it was new larger jets on the secondary side of the carb. I believe it got worse and started to smoke on heavy throttle. The car starts great, idles good, runs great at low to mid throttle, but pops back thru the carb on heavy acceleration. Is it possible my secondaries are now too large. "Too much fuel" should I get smaller ones ?
Seems like a small cloud of fuel comes out of the primary side when I rev it hard. Suggestions? Oh, the last jets I put in the secondary were 1429. Thanks.


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You have one of several problems which are, it`s running out of fuel, but if black smoke comes out thats not it. The cam is wore out, pop the valve covers, start it and see if you see any rocker arms that are making little movement compared to the others. Or lastly, the spark is dying off. However, I think your issue is the cam is shot. When you replaced the plugs did you make sure you got the firing order correct?

Just went thru this with my injected LT-4, turned out to be a fuel filter reducing flow causing the engine to go lean at WOT.

Anytime you get a backfire it's a good indicator the mixture in the cylinder is lean. This can be a restriction to flow like my filter issue, a fuel pump going bad, miss-adjusted float in the case of a carb, or something obstructing a fuel line somewhere.

The fuel cloud can be reversion which can be anything from the configuration of your new intake and how its relating to cam overlap, the exhaust system, or the boosters in you carb being miss-positioned relative to standing waves in the venturi.

I'd start simple with filters and carb float adjustments, then check the fuel pressure at the carb's fitting you should see about 4-6 psi at WOT.

Bogie

Pulled the valve covers on the 350,
I adjusted the valves while running, was very simple.
You guys were right, 1 rocker arm was hardly moving but wasn't loose or ticking. The previous owner had it adjusted as good as possible, if I made it any looser it wouldn't move at all, and began to run worse. If I made it any tighter the rocker still didnt move anymore and it began to run worse. So it looks like cam lobe is wore out. So, on a sbc 350 with aluminum intake and edelbroch carb and flowmasters what cam should I put in to get a little upgrade over stock and still be a daily driver? Instructions on install plus other parts I should relace in the process would be helpful. Of course money is a concern.Thanks.

In most cases I recommend a rebuild when this happens as you never know how much damage the cast iron grit from the cam caused. However if the engine still has good oil pressure I would just replace the cam. A good cam would be the edelbrock performer cam, 204 214 duration, smooth idle torque cam. Summit racing carries a identical cam for a much lower cost that includes lifters. I would add a double roller timing set while I was in there.
Before you start breaking the engine down, I would pour a can of sea foam in the oil and let it idle for about 15 minutes, then drain the oil as you`ll be adding new oil for the cam swap. Make sure you get some good oil additive to run with the new cam break in, as oils now have zinc and other anti wear additives removed which causes flat tappet cams to go flat.

yes, if hot oil pressure is still good then just swap the cam. and change the timing chain to a double roller while you are at it.

yes, the performer cam is a good mild cam (204/214). and works well with low compression, a stock valve train, stock converter, and a 3.08 gear. most likely what you have.

Use ZDDP oil additive with your new cam.

Great, so I can install the cam without having to change
valve springs, pushrods, or rocker arms? And I've already installed a
summit gear drive setup. It is the quiet one, and I'm very happy with it.
Thanks for all your help.

i agree with doublevision
THE CAM IS SHOT,END OF STORY
YOU ARE THE SECOND PERSON TODAY TO POST THE SAME PROBLEM

WHOA guy, what's with the shouting. I guess you aren't trying to make friends huh?

I just installed an Edelbrock cam as previously mentioned and along with the matching lifters ,double timing chain, and new oil pump and my old 350 is running real good. I used Rotella T 10 -30 and the cam broke in ok. I am looking for some ZDP additive which is not easy to find up here in the Great White North LOL. Good luck!
Clint

Napa carries valvoline vr-1 which has the necessary addatives for Flat tappet cams. I don't believe in mixing in addatives unless were talking about EOS and thats for break in only.