hey has anyone done a carter to q-jet swap on nailhead? I have finally located and purchsed the intake from 66, now I just needed some insight into what's involved in completting. I need an 800 cfm carb from late 60s early 70s and my ? is does it have to be a 455 Buick Q-jet or what.
hell if you've found a q-jet intake that wasn't an arm and a leg you've done the hard part. i've got a list somewhere around here with the best carbs to use on it i just gotta try and find it which could be a challenge. i've looked for one of those intakes for a long time with little luck of getting it with out paying an arm and a leg. i know where theres one locally but the old guy is trying to get out of the parts business and wants to sell cars and not parts. could probably buy the whole car for about what the nailhead is worth and then pull the good parts that are left and make a little money, but between the snakes and the ticks its a hell of a fight at this place. aircleaner and intake are there but the carb is missing. i'll look around tonight if no one has responded by then with the info you need...ken....
man, i left a spread bore intake/carb combo at the swap last week, i think it was $40!! IIRC. i know what those things go for! just not enough money to spend on stuff i don't need!
I'm confused by your stats there... You got a 66 intake for a Buick ("nailhead") and want to put a Q jet from a 70 or later Buick 455 (not a "nailhead") on it? I'm pretty sure Buick's Q jets started in '67 so a '66 manifold probably isn't a spreadbore intake and will need an adapter, or it's not a '66 intake. Here's a list of early Buick Q jets, http://pw2.netcom.com/~gnenad/quadrajet.html although Most all Qjets are basically the same with just different jets and rods and air door spring tensions for different engine sizes. In other words, if you find a good Q jet, use it! Cores should be free to $15. I have a half a dozen of then sitting around right now in various degrees of usefullness. I just pick them up when available cheap/free so I can collect the different metering rods and jets out of them, for tuning purposes. I ran a '73 Cadillac Qjet on a Chevy 400 SBC for years and currently have a '69 Camaro Qjet (with secondary rods out of a Cadillac Q jet) on a Monza 262" SBC. Get the Doug Roe "Rochester Carburetors" book on them and learn how they work Here's another site http://www.corvettefever.com/howto/53360/index.html?iam=sherlock_abc
Well DrJ it is a 66 Nailhead intake for a Q-jet. The one and only year and yes the first year as well. Any Q-jet is sufficient for your application. The new ones from Edelbrock (although expensive) are the best due to higher quality castings and metering. Good Luck
[ QUOTE ] Well DrJ it is a 66 Nailhead intake for a Q-jet. The one and only year and yes the first year as well. Any Q-jet is sufficient for your application. The new ones from Edelbrock (although expensive) are the best due to higher quality castings and metering. Good Luck [/ QUOTE ] Oh yea, my bad...and Chevy had a Qjet on a 396 in '65...bad memory, BAD!
As was stated any Q-Jet should be ok, but if you do want the 800cfm it came on 72 Buick with a 455. It's the hot ticket to most of the Nailhead guys. More info can be found at http://buickperformance.com/qjet.html
Thanks everyone for your help. I was wondering if any you also knew if it mattered if I have stock cam and pistons. I don't want to spend all this $$ and end up just over-carburating the car. Also i hear there is some modifications that need to be done to the carb to work on 401 rather than 455. Something about exhust valve? That could be wrong. Also there is a linkage/switch pitch. feel free to answer none of this if I am asking too much. Also no more post about how you've seen this at garage sales, swapmeets for 50 bucks, used as ashtrays or boat anchors it's gut wrenching... really.
Nailheads like big carbs, you won't be over-carbing the engine with a 800 cfm q-jet. Think about this, the nailhead 2x4 set-up is bigger than your single 800. Your stock pistons and cam are fine, don't worry. You can get any q-jet, they all bolt on, but depending on the original application can be 800 cfm or less. I think 650 is the smallest. A q-jet off any GM big block should have the 800 cfm rating. So you could look at Cadillac, Pontiac, Olds, etc. I think the main reason people like the Buick carbs is that the linkage is less trouble to mate up. Keep your switch pitch hooked up.
I'm going to have to agree and disagree with 38chev. I build several nailheads a year here and own several more. Even race one with 6 dueces. The stock 401 2bbl motor has a different cam, distributor advance, and displacement than the 401. The GS motors have a much healthier cam and more overlap and the 66 motors used a slightly different intake runner in the head than previous years. This was done for the Q-jet and the 2x4 motor. A 4bbl will wake up your nailhead but proper tuning is important and without a few critical changes it will not perform well enough to justify the upgrade. If you want to do nothing but add a 4bbl then install an AFB and go. You can sell the Q-jet manifold for enough to cover the cost. Good Luck. If you need anymore data please PM me and I will help in anyway I can. Good Luck Nailheaders and enjoy the best motor ever built.
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