Technical Demon carb help on a olds 455

I have searched and searched with no luck I have spent hours on hold with Demon and they never answer the phone or emails. Im having a hell of a time tuning this carb to my motor. If any of you guys can help I would greatly appreciate it.

Motor specs
1969 Olds 455 bored .060 over
Kieth black dished pistons
stock crank
stock heads shaved but I think only to clean them up
offy dual plane intake
Stock exhaust manifolds
stock vacuum advance distributor
Holley red fuel pump 7psi 96gph
mild cam (I don't know the specs)
36deg total timing @3000rpm
Mighty Demon 750 Carb with 84 primary jets and 88 secondary jets

The problem I am having is that the motor surges off idle until 3000ish rpm. The demon tech pages says that surging is due to a lean condition and to realign the*****erflies, check the floats and rejet if necessary. I started with a 72/83 jet combo and have made steps up to the current 84/88 combo. It is running the best it has so far but it still surges. Do I keep going up in jets or do I have another issue I am not seeing. I cant imagine that this motor would needs main jets in the 90s.

So do I keep upping the jets or toss the carb

Thank You

 

Oh yeah I have checked extensively for vacuum leaks and their isn't any

 

If you have a working Holley (or can borrow one..) swap that in and see if it improves. How do the plugs look? A surge like that points to a lean condition.

 

Put a smaller carb on that engine. The big one you have is for track day. get something in the 600cfm range (Street Demon).

 

Put the "Deamon" in the trash bin,,,get a good Holly or Edelbrock.....Hell,Barry Grant (the maker of Deamons)could not make them run right

 

I've got a 850 mighty Demon on my 460 and it runs great. I think what they mean buy realign the*****erfly's is to make sure you don't have to much of the idle transfer slot exposed. That will give you an off line stumble.

 

Switch to a Holley or a Quick Fuel. I have found most of the time, Demons are way more trouble then they are worth. Tech support is horrible!

 

Get rid of all of those junk carbs and get your self a Quadrajet and someone that knows how to tune it. Olds was made for the unique charasticics of that carb and nothing will run correctly on it. Those carbs are strictly for racing, not for street.

 

i would go to a holley 750 to 850. the 600 mentioned above is way to small for a 455, and besides they came with a q-jet around 850.

 

I would hook up a vacuum gauge to see what it shows then make sure you have the correct power valve.

 

2X^ sounds like you have the wrong power valve