My Street Demon 750 review.

[Cuprum-74]

I know this was hit upon by someone else before, but I'll add my Street Demon 750 experience. I love this thing! I've used Carter AFB's, Eddy Performers and Eddy AVS's in the past. I've tinkered a little with Rochesters, Thermoquads and holleys in the past (haven't quite figured them out).
I bought this Street Demon 2 years ago, it replaced the Eddy 650 AVS I had on it before.
It ran ok right out of the box but running extremely rich (I'm at 4500 ft elevation) After changing out the rods and metering jets using an AFR gauge. I left the secondaries as is (I might experiment with one stage leaner)

I have daily driven the duster for 4 years and even done a few 500+ mile trip in it (UT to Louiseville CO).
The AVS 650 was a good carb don't get me wrong, it was a refurbished one and it was good to me.
Between the two mileage was nearly identical the AVS 650 got slightly better mileage around town, 12-14 vs 9-12 (the 9 was because I was being a little "happy" with the secondaries). The highway mileage is about the same (varies between 16-17.5 while maintaining 70mph @ 3000rpm).
I have a hopped up roller cammed 360 from a 1990 Ram with speed pro pistons (.020 below deck, 9.7 compression), stock 308 heads (soon replaced with 2.02 ported J-heads), Lunati Voodoo roller (.515/.530, 219/227 @ .050), Weaind Action plus manifold. Beefed up A999 non-lockup trans and 3.21 peg-leg rear, (3.55 suregrip rear is no more... long story).
While the Street Demon does share alot of similarities with the Thermoquad there is differences. Thermoquad is spreadbore the Street Demon is not, it has a goggle valve secondary kind of like a three barrel.
There are definite AVS characteristics as well, hence why I picked up tuning on this thing quickly as well.
Cold weather starting (so far at 20 degrees) is excellant. MSD ignition helps too.
All in all I am very happy with this carb. It doesn't quite have the "growl" when you hit the secondaries like the thermoquads do however so I was (very) slightly dissapointed.

 

[1994redram]

I have the same carb. I had the 625 version and now the 750. I’m pretty happy with it. Mine ran rich at cruise and at WOT. I started leaning out the primaries and it still runs rich at part throttle but is pretty spot on WOT. I’m getting ready to do a head and cam change so I’m not going to dial it in any further.

 

[jimjimjimmy]

port the 308's leave the j's where there at.. jmo. I hear good things about those carbs .

 

[thesiren74]

Very reliable, we just put it on and adjust the idle mixture screws and haven't touched it since july.

 

[12many]

While, in hindsight, I should have gone with a more drag race oriented carb for what I'm doing now with my ride, I've tuned on the Street Demon 750 with an invaluable AEM afr gauge and can't complain about how it performs. It came jetted rich, for my setup. With the aid of the AFR, and the jet kit its as spot on as I think you could get. Hot/cold, one pump of the throttle to set the choke when cold, maybe a half pump when warm, sometimes I dont even touch the throttle, and it fires right up, idle is strong and even. I've run a 12.19@107+ with it, might get better from a more race oriented carb, but it is a "street" carb.....only complaint? The "E" clips. They suck. Otherwise, thumbs up

 

[thesiren74]

While, in hindsight, I should have gone with a more drag race oriented carb for what I'm doing now with my ride, I've tuned on the Street Demon 750 with an invaluable AEM afr gauge and can't complain about how it performs. It came jetted rich, for my setup. With the aid of the AFR, and the jet kit its as spot on as I think you could get. Hot/cold, one pump of the throttle to set the choke when cold, maybe a half pump when warm, sometimes I dont even touch the throttle, and it fires right up, idle is strong and even. I've run a 12.19@107+ with it, might get better from a more race oriented carb, but it is a "street" carb.....only complaint? The "E" clips. They suck. Otherwise, thumbs up

My brother ran pretty good when he used this carb on his 408 barracuda i believe he ran 12.20s @109, when swapped cams and put on the 850 race demon we got it to go 11.80s @114/115.