Is there much difference between the manifolds for single 4 barrels. Specifically I am curious because I have access to a 63 manifold and a 66 manifold for an AFB. I wondered if they flowed any different or if they had differences to do with the switch pitch on later cars.. The only thing I know is they have different casting numbers. Thanks
I think they are all pretty similar. The factory manifold from my '62 and the later '66 manifold I have laying around are indistinguishable.
The basic differences are in t he ''spread'' between the different series,,,, 264, 322,,, 364, 401/425.... because the deck height changed to get the increased stroke and so the bigger the engine cubes, the wider the manifold....but I dont know exactly how that breaks down....
My 63 manifold was a little different than the 65 one in that the coil mount had only 1 mounting hole. I think the 65 had 2 if I remember right. I know something was different.
The "spread" on the manifolds is: 264 and 322 8 1/2" between bolt holes; 364 is 8 3/4 ", 401 - 425 is 9".
I haven't compared the Buick manifolds, but among the Chrysler LA manifolds the ThermoQuad (spread-bore) is definitely better - more plenum area due to the much larger secondary bores. I suspect the QuadraJet manifold is ahead of the AFB manifold for the same reason, not to mention higher stock carb CFM capacity.
Ok thanks guys. Yeah I was speaking about 401/425's. I would love to get a qjet manifold but they seem a litle hard to come by.
You have to remove the search term that makes it expensive, not even "nailhead", instead say "Buick manifold", and read through all 900 items. You'll find one that is: 1. cheaper because the seller doesn't know it's special 2. cheaper because fewer people found it
Chris, EELCO was working on a new aluminum intake for the 401/425s. I haven't heard anything about it in a while. I don't think they were making a spreadbore. I don't think they released any flow numbers either, but if your not in a hurry you may want to check with them. You can find an affordable spreadbore on here, if your patient. Craigslist is also a good source, but use Search Tempest. It searches Craigslist, but allows you to search multiple cities within a set mile radius from you. Check out Gesslers website and the work they do on intakes and somewhere on here there is a thread of Doc's "hogging out" the front/rear divider trick :laugh:. This will help the flow on any intake, but Doc likes the spreadbores.
Actually , Doug, I like both styles,,,, the ''Doc dual plane'' was my attempt to experiment at making a single 4 manifold flow more... I did it , changing nothing else at all, and was amazed at the difference....EElco has been talking about a aluminum single 4 manifold for at least 2 years that I know of but nothing ever shows up... Talk is cheap but whiskey costs money.... My favorite carb is the holley 3 barell and it has to use a sq. bore configuration... i have purchased a tig welder and intend to make a fabricated aluminum manifold that will take any carb that is made by changing the top plate... for a nailhead,,,:laugh: :laugh: any carb from a 2 bbl on up to and including webbers...multiples,,,, but I have got to get rid of some of t he projects that I have going now and also learn to use this Tig set up.... But, i have given up on Eelco.... they aint going to do a single 4 for a nailhead.... or it would have already been out there.... I will go for the dual plane concept... The info on the intake mod is in the wrenchin secrets section as a sticky....:Brow:
The Q-Jet manifold is the stock one on a 66 Riviera correct? If it is, I guess that's what I have. It has a Holley on it now, but with an adapter plate. Or, did they make 2 single 4 barrel intakes for the 66 Riv? A q-jet one and an AFB one? I'm confused...
The QJ Manifold I have is from a '66 Wildcat GS. But I also have a AFB Style Intake from a '66 Skylark GS & a AFB Intake from a '66 Electra. Doug
The 425 engines in the Riviera and Wildcat came stock with the Quadrajet. There was a mid year option Skylark series GS that could be ordered with an optional Q-jet equipped 401 as well. (Actually, there were no engine options for the Riviera, all Rivieras were equipped with the MW engine.) There was a mid year option for the MZ engine which came equipped with the dual four barrel engine.
Thanks for all the responses. I actually have dual quad setup on it now but they both need rebuilds. THe car is just a summer driver so I figured the 4brl would be better for driveability and tuning. I have been waiting for that eelco manifold but I want to be able to drive this thing this summer so I'll probably just do a doc dual plan with and AFB or newer edelbrock.
