Best Carb?

[airboatgreg]

It's funny you should mention that. I'm in the middle of rebuilding a Q-jet carb, but at a standstill because there seems to be too much play in the primary throttle shaft. It's pretty much done except for rebushing the baseplate.
If you have a decent source for the parts, or have extras that you'd be willing to sell, I'd be interested.

OCD can be a good thing. I have the bushings and the screws(and put my hands on them) If you have not done this there is a couple of things you need to be very careful of. Private message me an email address and we can correspond that way and better yet lets touch base on the phone so I can send you the stuff and walk you through it. I am sure you can do it but I have done this many many times when I had my shops and it can be screwed up quickly. Longroof79 you are a great contributor to this forum and I will be glad to send you the stuff.

 

[Longroof79]

OCD can be a good thing. I have the bushings and the screws(and put my hands on them) If you have not done this there is a couple of things you need to be very careful of. Private message me an email address and we can correspond that way and better yet lets touch base on the phone so I can send you the stuff and walk you through it. I am sure you can do it but I have done this many many times when I had my shops and it can be screwed up quickly. Longroof79 you are a great contributor to this forum and I will be glad to send you the stuff.

Thank you so much, Greg.
I will PM you and we'll talk further.

 

[bracketchev1221]

I like aed and quickfuel for out of the box stuff. I think a 750 is fine for being a cruiser. It’ll be small over 6000 on a 427 so that is something to factor. I ran an 850 on a 615 hp 383 and a 625 hp 427.

 

[Clone TIE Pilot]

With Qjets baseplates you can make your own bushings out of Teflon sheets which seal better than metal bushings. This way the passenger side requires no drilling and the driver sides only drilling out to the next bit size. The passenger side boss is really thin and can easily crack if drilled larger for a metal bushing.

 

[Longroof79]

With Qjets baseplates you can make your own bushings out of Teflon sheets which seal better than metal bushings. This way the passenger side requires no drilling and the driver sides only drilling out to the next bit size. The passenger side boss is really thin and can easily crack if drilled larger for a metal bushing.

I remember there was a thread about using Teflon strips to take up the play in the throttle shafts. I agree, it's a pretty non-invasive process, but you still need to disassemble the throttle plate(s) and remove the shaft. http://rmcavoy.freeshell.org/Q_Jet_bushings.html

 

[383_GrandPrix]

as per the rules we ran a 500 cfm 2 bbl on our 604 crate which is a 350 with aluminum heads, angled plugs and the rev limiter set at 6300 rpm. We never ran out of fuel even on the longest straights. This is one of our cars with the 604 crate, first time out that year just testing at a small track

Looks like there was wrinkle in space/time as he came into turn 1

 

[Jim hopper]

I have a holly 750 on my 383 stroker and it ain't too much for mine it should work fine on your 355 or 427

 

[Jim hopper]

Nope

 

[Clone TIE Pilot]

I remember there was a thread about using Teflon strips to take up the play in the throttle shafts. I agree, it's a pretty non-invasive process, but you still need to disassemble the throttle plate(s) and remove the shaft. http://rmcavoy.freeshell.org/Q_Jet_bushings.html

I also found it still requires drilling on later CCC carbs. The stepped bore is very shallow on the driver side shaft bore and must be drilled deeper on CCC carbs, but not nearly as wide as a metal bushing would require. The stepped bore on the passenger side is just as deep as older non CCC carbs so that side does not require drilling.

I guess GM reduced the stepped bore on the driver side to increase bearing surface due to the side load caused by the return springs for later Qjets.

 

[vanrah]

Greetings Ham & all; My $.02 cents worth. Holley style carbs are easer to tune & more prone to leaking from little use. Q Jets are much more complex to tune due to the piston spring needing to be in tune with the cam then it's on to rods with steps poking into the all four jets, pain in the posterior. And because of the single float bowl are much more sensitive to fuel volume. If you're after part & light throttle metering ya can't beat a Q Jet. If ya want easy to tune & great equal flow to all cylinders a Holley style is your only choice! As for size GM put a 780 CFM vacuum Holley on a Dz 302 Z-28 & a very similar 780 on the L78 375-396, L72 425-427 & the mighty Ls6 450-454. All solid lifter engines, sure the 302 & L78 would rev 7000 right off the show room floor & the two larger ones would push 6500. The key word here is VACUUM secondaries, easily tuned with a spring kit. The only way I would consider a mechanical secondary style Holley is if the car was under 3300 Lbs, had 3.70 or tighter rear gears, this is where TOO Big will Bite you very quickly. I'll post a picture of my solution, it works Very well indeed. Ole' Bob.
Ps: Something like this would work on both engines & you would only spend money once. Plus you would only have to plumb it once.