[ho428]

Just posting some feedback since this was a hot topic awhile back.

I'm running a Northwind on an 11.5:1 407, KRE 290 heads, Pro 750 with 82-86 jets, under a VFN 400 Firebird hood. Fits fine even with a 1/4" spacer and 3" drop base breather.
Power is incredible but she gargles below 3400 when feathering the throttle in and out of the turns, but from around 3800-6500 it has a great curve and pull.

I don't think it's too big for this engine afterall, I wouldn't want to run it on the street though.

[shaker455]

Originally Posted by ho428

Just posting some feedback since this was a hot topic awhile back.

I'm running a Northwind on an 11.5:1 407, KRE 290 heads, Pro 750 with 82-86 jets, under a VFN 400 Firebird hood. Fits fine even with a 1/4" spacer and 3" drop base breather.
Power is incredible but she gargles below 3400 when feathering the throttle in and out of the turns, but from around 3800-6500 it has a great curve and pull.

I don't think it's too big for this engine afterall, I wouldn't want to run it on the street though.

If you have the room a 4-hole spacer may help you out down low.

[twinturrbo406]

Originally Posted by ho428

Just posting some feedback since this was a hot topic awhile back.

I'm running a Northwind on an 11.5:1 407, KRE 290 heads, Pro 750 with 82-86 jets, under a VFN 400 Firebird hood. Fits fine even with a 1/4" spacer and 3" drop base breather.
Power is incredible but she gargles below 3400 when feathering the throttle in and out of the turns, but from around 3800-6500 it has a great curve and pull.

I don't think it's too big for this engine afterall, I wouldn't want to run it on the street though.

... that manifold is very comparable to a ported Trqr-II intake, i'd say you really need one of my carbs, you would be very happy driving that setup around ... ... i did a carb for a customer that drives his car a ton, 3.23 gears, 2,200 convertor(lock up) TH700r4, hyd. rollr. iron d-ports that i worked, 455, it runs 11.90's and cruises at 80mph !!! ... throttle response is awesome on his car also !!! ... and his car is totally stock suspension, shocks and all ... spins pretty bad ... only gets 1.80 60fts ...
... IMO your issues are carb related ...

[Aaron Quinton]

The Northwind intake is nothing like a torker II intake. I have a Northwind that I couldn't make work with the shaker scoop on a TA. I had to move the the Torker II to make shaker height work. The plenum on the Northwind is significantly larger than the Torker II. The inlet area of the runners is much larger than the Torker II as well. The plenum on the Northwind has no exhaust cross over either. The Torker II is a warmed over street/strip manifold that does the job. The Northwind is a reduced carb height race intake. The Northwind has many of the Victor plenum mods cast in. Here are some links to dyno data with the Northwind intake: http://www.sdperformance.com/newsStory.php?newsID=53

I'd work on the carb tuning before changing intakes on your application.

[ho428]

The 4 hole 1/4" spacer is all that will fit under the hood. The Carb seems to be working much better since I jetted it up and went beyond square on the rear.

The gargling at low rpm is basically what you see in Road racing with a carbed engine, and being a Pontiac I probably run the rpm range lower than most.
It's not really hurting the performance since it takes off on turn exit fine without stmbling, but I think it'd be tough to run that intake on a street car that spends a lot of time down low.

[cutrone]

I'm running a Northwind on a 310 KRE head 461 with a out the box 850 dp
Solid street roller 254/260 --620 lift . About 550 Hp

With a 1" Wilson spacer it idles at 750 rpm's no loading up at low rpms and is "smooth" pulling all the way to 6000 . It has a lil less low rpm torque than the RPM intake that it replaced. Northwind & 1" spacer is about the same height as an RPM and a 1/2" spacer.

[twinturrbo406]

... well, the car i was mentioning, ran the same ET's and .5-.7 mph faster than my ported Torqer II, so the owner sold it because he could get more money for the new intake ... but the car drove the same ... no traction at all ...

[Skip Fix]

His 400 is for sure different than a 455/461. Try one and tuning it and you will see. My RAIV 400 swapping from a ported HO intake to a Torker I lost so much bottom end and 60 ft with a 4500 stall I could not tune it back to the times eventhough it picked up 2 mph.

[JoePapa]

I wonder how the Pro 750 PV and emulsion jet sizes compare to a standard 750. I normally run a 825 mighty demon on my 400 and it was fine but it seemed a little off on the street and this showed on my LM1. I borrowed a friends 750 and it's much crisper on the street in the part throttle and lower RPM range. I'm currently running the Northwind with no spacer.

[moparcolt]

does the northwind fit under the firebird 400 hod?
Does a performer RPM fit under the same 400 firebird hood?

[Chupa]

Originally Posted by moparcolt

does the northwind fit under the firebird 400 hod?
Does a performer RPM fit under the same 400 firebird hood?

Yes and yes..... but the real question is will an air filter fit on top of the carb with it. Your in the race section many guys dont run filters. I have a victor with a 4150 under a 400 hood. maybe 1.5 - 2 inches on top of the carb (i know, I know the carb probably doesnt work right, I do use BLP vent tubes)....

so it kinda depends, I used to run a RPM with a drop base cleaner, It worked...I think the hood was touching the cleaner top.

[BruceWilkie]

Originally Posted by Chupa

Yes and yes..... but the real question is will an air filter fit on top of the carb with it. Your in the race section many guys dont run filters. I have a victor with a 4150 under a 400 hood. maybe 1.5 - 2 inches on top of the carb (i know, I know the carb probably doesnt work right, I do use BLP vent tubes)....

so it kinda depends, I used to run a RPM with a drop base cleaner, It worked...I think the hood was touching the cleaner top.

I ran the rpm with a 1/4" spacer/insulator and drop base with 3" filter without ever touching on my 68 bird.

Same exact rpm/holley/aircleaner setup on my wifes 69 I couldnt run the spacer or it would sometimes rattle against the hood. I figure its production variences of installed sheet metal heights and possible motor mount variences/tolerance stack up.(I pretty much rule out sag I had new mounts vs hers were still original 69's) Besides different years even if hoods and subframe are similar.

When she had dual quads the cleaner top was actually a little bit higher in the center(measured from valve cover) but being long oval it cleared the hood just fine, about 1" on one end maybe 3/4" on the other. Its the outer edges(twd sides of car) of the 14" cleaner that hit not the center.

[Chupa]

Originally Posted by BruceWilkie

I ran the rpm with a 1/4" spacer/insulator and drop base with 3" filter without ever touching on my 68 bird.

Same exact rpm/holley/aircleaner setup on my wifes 69 I couldnt run the spacer or it would sometimes rattle against the hood. I figure its production variences of installed sheet metal heights and possible motor mount variences/tolerance stack up.(I pretty much rule out sag I had new mounts vs hers were still original 69's) Besides different years even if hoods and subframe are similar.

When she had dual quads the cleaner top was actually a little bit higher in the center(measured from valve cover) but being long oval it cleared the hood just fine, about 1" on one end maybe 3/4" on the other. Its the outer edges(twd sides of car) of the 14" cleaner that hit not the center.

I do have the aluminum body mounts - I think that drops it a half inch... That could account for the difference...

[Cliff R]

How close is the air cleaner lid to the top of the carburetor?

I've tuned set-ups here where folks were using spacers or tall intakes that put the carb up pretty high, combined with drop base air cleaners that placed the air cleaner lid pretty close to the carb.

If it's too close it can induce low rpm stumbling, hesitation, etc.

I agree that the problem is carburetor related, not specifically the intake.....Cliff

[ho428]

I'm using a drop base Aluminum breather with 3" K/N filter, no chock horn on the carb. I haven't measured the clearance but it looks sufficient, I'll put a ruler on it next chance I get.
I have a 1/4" heat shield spacer under the carb and it fits under a glass 400 hood with maybe 1/4" clearance at most.

At a new track the other week I started having issues in a long LH sweeping straight running at about 1/2-3/4 throttle, secondaries were probably cracked open a little. We determined I'm getting fuel dumped out of the vent tubes, probably going to do some sort of hose connection on them, but hose loop clearance may be an issue.
First time I've ever had the problem, first time on that track as well. Felt like a fuel pick up issue but everything checked out. Depending on the lap and throttle position some times it didn't do it.
Couple of old timers said it sounded like a typical Holley issue on a road course. Learn something new all the time.

I remember seeing a dyno video awhile back the showed on the dyno run fuel being pulled out the vents, anyone remember what that was? Like to see it again.