Mighty Demon 750?

I may be opening a giant can of rabbid worms here...

Ive done a lot of searching and it seems these have a bad reputation. (Thats putting it mildly)

Ive never owned one, but Im looking at a used 750 Mighty Demon with downleg boosters. Looking to put it on a mostly stock '69 460, but I may build it up some down the road.

Ive heard the stories of metal inside left from machining, and being super rich out of the box. Horrible customer service, and Barry Grant "tried to kill me"...?! The one in the urinal cracked me up..

BUT..this one is...used, and like half price of new.

Im more of an Carter/Edelbrock guy, had a Holly double pumper back in the day was a leaky POS.

Heck, i liked my Quadrajets too. Yes, I can tune a carb...

Any carb is going to suck if it isnt tuned right, no matter what brand....so...

Constructive opinions?

Holley's have come a long ways since the old days. They don't use those crappy paper gaskets anymore!! LOL
The Holley HP series carbs are pretty darn good...they incorporate many of the things that used to be considered "tricks" back in the day to make them perform better.

I have a brand new Barry Grant Demon carb 750 CFM right out of the box.
Put it on a mildly built 390 FE and no matter what I did, it would not idle smoothly, and at part throttle it had this very annoying surge up and down in RPM.
Took it apart for inspection and its a total mess. I mean things are machined wrong, passages don't line up between the main body and the metering blocks, the emulsion well circuit looks like a 5 year old prepared it, the throttle shaft leaks air (vacuum leak), etc.

Brand new!!

So I purchased a Holley HP double pumper (4 speed car) and it starts and runs flawless!!
This is just MY experience. I cannot bash every single BG carb.

Ok thats a good start. I dont mind fiddling with stuff. If i didn't, i wouldn't be into Hot Rods.

Turns out, this is like a third of the price as new, and I'm working on a barter. Gotta love Craigslist lol.

Seems way too cheap to pass up, even if it needs to be gone through. Im sure i could work with and tune it. Thats half the fun...

I know many who have had problems with the Demon carbs, I bought two of them new in the earlier days, one was a 650 Demon that replaced a thermo quad on a BB Dodge Ramcharger FT 4X after the change with a little tuning, it would light up all four for over a block on dry pavement, the other was an 850 Demon on a Cleveland that has seen 8500 many times and is bottle fed, it needed some tuning too, but it flames up like a new car, and don't fall over on the big end I still use that one. I believe the earlier ones were solid and quality the control was good, they grew too fast too soon and mistakes were make when the demand increased. I have heard all of the bad stuff but the two I bought were exactly what I wanted, I have moved on since but they deserve the respect of making a really good carb in their day. JMO

Well...I'm picking it up tomorrow.

I could NOT pass up on the price. Even if thing has been gutted its still seems worth it. This carb lists for $749 at Summit. Ive seen remans on ebay for around $500. Still way less...

I won't even say what I'm paying, but couldnt even hardly find an Edelbrock cheaper. Again, gotta love Craigslist. People sell what they don't even know what it is they have.....

Hope i dont somehow regret this, but probably not. Ill let y'all know

Craigslist ?? Take a gun!

I used to go to breakfast with a friend of mine every Saturday; still do once in a while.  He always wanted to go to this one family restaurant.
When leaving, he would always make snide remarks about the taste of the food and how they really need to prepare it better.

One morning I confronted him ... this is the place YOU always choose to go and I have to listen to you afterward complain all the time about their sub-par food  Why are you so insistent about going there ...?

His answer was that they give you so much food and it is not expensive at all.
I am sure I would rather go somewhere and enjoy the lesser amount of what I got.

This is the kind of irony I am reading here.

Interesting story.. I kind of see where you are going with that. Kinda...

Guess its like buying 20 cases of prune juice just because its on sale, and you don't even like prune juice?

Ive used Edelbrock, Holly, Rochester, Autolight, etc because its what i had. Right now, i dont have ANY carbs, so its like starting from scratch.

Really though..how bad could it be? Ive worked on a fair share of different brand carbs. They all have their plusses and minuses for tune ability i think its all in the learning curve for the specific vehicle it is on.

That, and i have convinced myself i could make my money back if i didnt keep it. Yea, ive got issues lol

EDIT-

I MAY be coming to my senses. A 'race' carb on an orherwise stock motor doesnt seem logical. My thoughts of downtuning it to make it work are likely flawed. To build an engine around a carb is completely backwards. But...SO cheap.

Hmm...decisions, decisions..


Any and all comments welcome, thanks.

Well, I guess I'll jump in


I have(still) a 1095 King Demon, that I've never had a single problem with .
Any issues with it, were nothing a simple rebuild wouldn't fix..

Just my experience, I know of others who have had issues...

I had a 750 I bought new back in the day, had nothing but problems with it, just flat couldn't be tuned. Tried talking with BG and was met with an attitude and a FU from him.

Came to find out later they had a number of quality issues with shavings and bad / miss machine parts. And ultimately all of that put him out of business.

Just be forewarned their are lot of duds with those carbs, but you can get great ones too.

If I have a carb that works great, I'm sure as hell not gonna sell it on craigslist.

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I don't think you could have a problem with it that wouldn't be fixable. I have a 750 on a 351 that's never had a problem.these things all work basically the same and sure ain't complicated.

I saw an add that Barry Grant was back in business fixing and building Carburators. There you have it, the American dream, fab crape equipment and then charge you former customers to fix it.

Well....i passed on it. Too many what ifs, hows and whys. A friend of mine didnt take long to talk me out of it. Too cheap, and was from what i would consider a kid. Yea....no thank you.

I ended up getting a Holly from my friend. By the book its a 3310-2 so....4160, 780cfm vac.sec manual choke. Dual feed, not dual pumper.

Ill see how it runs before i rip into it. Unless my bench test -fill carb with gas, see if squirters squirt- don't...squirt, then i will.

Im assuming it may be a little fat as is, but it was last installed on..unknown engine.


But....its not a Demon. I'm ok with that.