Holley or Demon??
I used holleys for years and 2 years ago I thought I'd try a Demon. Their venturis were smoother and I just love the sight glass that you can see the fuel level without pulling a plug and puking gas all over a hot engine. Maybe Holley has gone to sightglasses now, to late. I've heard some buyers of Demon's found crap in the float bowls right out of the box but I haven't. I started with a 750 vacuum secondaries and then switched to a 750 full mechanical D.P. to get rid of a off idle stumble. I had to rejet both carbs once, down one size, other than that no problems. Actually I did have a problem with the first one, I couldn't control the fuel level in both bowls. Hooked up a pressure guage and was seeing 10 psi just after startup. Fixed it with a regulator set to 6 psi.
I used holleys for years and 2 years ago I thought I'd try a Demon. Their venturis were smoother and I just love the sight glass that you can see the fuel level without pulling a plug and puking gas all over a hot engine. Maybe Holley has gone to sightglasses now, to late. I've heard some buyers of Demon's found crap in the float bowls right out of the box but I haven't. I started with a 750 vacuum secondaries and then switched to a 750 full mechanical D.P. to get rid of a off idle stumble. I had to rejet both carbs once, down one size, other than that no problems. Actually I did have a problem with the first one, I couldn't control the fuel level in both bowls. Hooked up a pressure guage and was seeing 10 psi just after startup. Fixed it with a regulator set to 6 psi.