Cliff's Quadrajet Parts and Rebuild Kits

General Category => Quadrajet Carb Talk and Tips => Topic started by: dualquad on October 12, 2025, 07:54:02 PM

Title: Q-jet on 496bbc
Post by: dualquad on October 12, 2025, 07:54:02 PM

I am building a 496 bbc for my 69 chevelle. The motor should be approx. 600hp. I would like for it to appear to be a 396 350hp, so I plan on using a factory cast iron high rise intake with a Q-jet. My question is, what should I do for the fuel delivery system? Is anyone running a Q-jet on a 600hp street car? Looking for recommendations from those that have experience with a similar set up. Thank You.

Title: Re: Q-jet on 496bbc
Post by: lightning boy on October 13, 2025, 04:44:11 AM

You're going to need an in tank pump with 8AN lines on a return style system with a regulator.
If you go this way you won't have any problems.

Title: Re: Q-jet on 496bbc
Post by: dualquad on October 13, 2025, 07:12:59 PM

I had thought about adding a 1/2" supply line (which I believe is equivalent to 8AN) and using the factory 3/8" line for the return. Would that be ok? Or does the return need to be the same size as the supply?  Also, any recommendations for a pump?  Thanks

Title: Re: Q-jet on 496bbc
Post by: lightning boy on October 14, 2025, 05:09:00 AM

IF it were me, I would get a new tank if they make one for your car. Most of the companies are going to have a pump to meet your Hp level. If not you'll have to cut and weld a sump in your tank and install a pump. A real Bosch 44 not a Chinese knock off, would be good, or a Denso unit from a mid 90's Toyota Supra would feed anything to 700HP. Yes IF your motor is really making 650HP you want a 8AN line back to the tank as well. Don't put any filter on the suction side of the pump. Just use the sock that comes with it, and mount the regulator return style after the carb.

Title: Re: Q-jet on 496bbc
Post by: 77cruiser on October 14, 2025, 06:19:20 AM

I have this in tank pump.  https://www.summitracing.com/parts/avm-50-1000

This fuel pressure regulator.  https://www.summitracing.com/parts/aei-13301

Title: Re: Q-jet on 496bbc
Post by: Cadman-iac on October 14, 2025, 03:27:10 PM

Quote from: 77cruiser on October 14, 2025, 06:19:20 AM

This fuel pressure regulator.  https://www.summitracing.com/parts/aei-13301

 That's a really good pressure regulator, and the best part is it's American made.

 I do see just a slight amount of pressure variation with the temperature, about a pound or two at most from what I've seen so far. Does yours do that at all?

Title: Re: Q-jet on 496bbc
Post by: 77cruiser on October 14, 2025, 05:30:38 PM

Seems to hold steady @ 6.5 lbs. Gauge is under the so I can't check it at WOT.