Technical Holley Quick Fuel

New guy question
Looking to replace the Edelbrock 600 on a 355.I already change the heads out to AFR 195's along with a Edelbrock RPM Performer dual plane and a Howards mechanical roller with 1.6 roller rockers. Don't know anything about the cam,it came installed with the 33 Willys. Been looking at the Holley Quick Fuel HR 650 mainly because of the sealed ****erfly shafts they say it has.Just wanted to know if these carbs have been holding up after time.

 

Yes, quality parts.
I've got one on a running 493 inch engine, one on a 259 inch engine, and a "pair" on a cross ram manifold for a high dollar 299. inch engine.

The one on the 493 works great, snappy throttle response, no leaks, easily adjustable (didn't need a lot of adjusting !).

Mike

 

On a 355 that's a pretty deep breathing set of cylinder heads.
Don't be afraid of a 750cfm carb.
Even a small solid roller cam and it's going to love to spin up.
What's the compression ratio?

 

The bottom end is stock with the normal four valve pockets in the pistons.So it should be 8:5 the specs. with the AFR heads they say it will be in the area of 9:5 .I used the metal shim stock head gaskets and they are .020 thick to help gain a little more.The carb size I been going back and forth on and can't really decide,I do want as much carb as the engine will handle.The car has a Winters quick change rearend at a 4:11 ratio and a Tremec 5 speed.So like you said it mite be able to handle the larger carb.
Thanks for your guys input,it helps a lot.

 

Got a ride that has a pair of QFTs on it. Pulled them off and did a look see along with changing a few parts. I am not a big Holley fan, but these address a lot of the things I don't like on H brand while still having the design and tuning aspects. A big thumbs up for the brand.

 

I'm running that same QF 650 on my SBC 350 in my '39 Chev. Running a pair of Dart 180SHP heads, same intake as yours, and Howards hydraulic roller cam with .525"/.530" lift, automatic trans, and Ford 8.8" with 3.73 gears.
I've had it on there for 3 years now, and done changes to jetting and hi and low speed bleed screws to tune it to my engine. Once tuned it's ran great with no issues. I love all the extra tuning features of this QF carb.