Holley Street Demon 625
 

I'm fed up with trying to get my Computer controlled Quadrajet to work properly, so i was looking into replacing it for a traditional carb and vacuum advanced distributor. I came across the now made by Holley Demon street demon 625cfm model 1900 carb. It looks to have both square and spread bore holes so i can just keep my factory manifold. Anyone have experience with running these in a third gen? Should i go that route or look at an adapter plate and out an edelbrock performer carb on?

Re: Holley Street Demon 625
 

I have had fitment/ clearance issues with those AFB-Style Demon Carburetors...
when the Spread-Bore Intake Manifold has a WIDE Center-Divider that is tall enough to be even with the Carb Mounting-Pad.

The Design in the Image below, will work with the Demon Carb:

https://cimg2.ibsrv.net/gimg/www.thi...1cf10e36a9.jpg

The Image Below (Most Stock Designs) will not fit:

https://cimg2.ibsrv.net/gimg/www.thi...12c3b82a4e.jpg

Re: Holley Street Demon 625
 

It's for my factory lg4, so you're saying my factory intake won't work

Re: Holley Street Demon 625
 

Correct.

The Demon Primary Throttle-Blades will hit the Carb. Mounting-Pad of Intake-Manifold... and will not open.

Re: Holley Street Demon 625
 

You should be able to use an Adapter/ Carb-Spacer that will allow the Demon the install on the Intake-Manifold.
It would not be ideal for Performance purposes...

I would contact Holley (regarding an Adapter for the Demon Carb to fit the Spead-Bore Intake-manifold) to be certain.

Re: Holley Street Demon 625
 

Yea I'm really thinking about just getting a new intake manifold, question then is do I stick with the demon or get an edelbrock 1406

Re: Holley Street Demon 625
 

Personally... I would not matter much to me.

Re: Holley Street Demon 625
 

Ok next question, what should I do about the change in fuel lines. I know the factory fuel line will not work. What size is the line the threads into the mechanical fuel pump