305 V-6 with dual Strombergs

[sailed2japan]

I think that LMC actually sells a header for v-6's. This will be one cool motor in my book

[Corts60]

OK. I'm home, and here are the carb's and header flanges:




To my unfortune, I have to drive my '60 daily for the next couple weeks while I get my '76 Nova SS on the road for my daily driver...

What do you think about the set-up?

[19GMC63]

Originally Posted by 4dranch

you don't have to worry about that...
you have a nice rig just the way it is..

He speaks 'da truth.

[Corts60]

OK guys, I'll be ending this thread and starting a new one just for the scoop and associated fabrication for it to be a true cold air induction!

Thanks everybody for all the help, criticism and comments!

Here is the new thread: http://67-72chevytrucks.com/vboard/s...d.php?t=361058

[texanidiot25]

Will dual carbs help breath air when their choked down back to the same size holes as the regular single carb?

But, for looks, saweeeeeeet.,

[4dranch]

Cort..That looks so freaking cool....
Whats the overall height???

[Corts60]

Originally Posted by texanidiot25

Will dual carbs help breath air when their choked down back to the same size holes as the regular single carb?

But, for looks, saweeeeeeet.,

I'm not sure, I've never done it before......but you can ask 60 years of hot rodding......

[Corts60]

OK boys....The first pic is the stock one barrel and oil bath air filter at just over 8". Forgive the pic, it's night out.
The second pic is of the assembly without the adapter at 9.125"....
The third pic is of the assembly with the adapter at 10.375"....



If I go without the adapter I have to drill and tap a center hole in the intake, if I go with the adapter, I will have the carb's sit just outside of the hood...
And I have no idea what filter I'm going with yet......HELP HERE!

[Fred T]

Originally Posted by texanidiot25

Will dual carbs help breath air when their choked down back to the same size holes as the regular single carb?

It's old hot-rod technology. As long as the airflow doesn't get disrupted, velocity will increase to provide the needed air. One thing that was done was to place a riser under a carb, old bottle jack bodies were used since they had a flange on one end. Increasing the air speed entering the engine shortens the time needed for filling the cylinder and allows the engine to accelerate faster.

[texanidiot25]

Originally Posted by Fred T

It's old hot-rod technology. As long as the airflow doesn't get disrupted, velocity will increase to provide the needed air. One thing that was done was to place a riser under a carb, old bottle jack bodies were used since they had a flange on one end. Increasing the air speed entering the engine shortens the time needed for filling the cylinder and allows the engine to accelerate faster.

Sorta like a tunnel ram intake eh?

[19GMC63]

looks awesome.
I too am curious on the height and what your going to do for an air cleaner(s).

[jonzcustomshop]

I would try to keep it under the hood if possible, without the adapter how much room to the top of the hood?

if not you might try that big ford truck scoop from 60-63 that they used on the superduty pontiacs, I think they might repro them...they would look period correct.

If you are ever in the missoula area, we could run up to kellys wrecking yard, he has a few of those 60-61 gmc hoods, I just think the shipping on one of those would be huge.

[jonzcustomshop]

Originally Posted by jonzcustomshop

if not you might try that big ford truck scoop from 60-63 that they used on the superduty pontiacs, I think they might repro them...they would look period correct.

what I said!!
btw 62 gmc hood is different... your style is 60-61.
I would snoop around on some pontiac websites about that scoop... they used it on the superduty ponchos, and GM even gave it a GM part #.

[justcuz]

Jon you are right, however you stuck it in the middle of your post with no pictures. Cort could not visualize it!

[Corts60]

Yeah, I really want another 60-61 GMC hood to cut up but they just ain't easy to find....

[jonzcustomshop]

so would the optimum shape of that adapter be a V to disrupt the air flow the least?

[Corts60]

Originally Posted by jonzcustomshop

so would the optimum shape of that adapter be a V to disrupt the air flow the least?

That's what I was thinking too...The first manifold I wanted was the Y manifold pictured on the first page, but turns out those are on permanent back-order....

[Fred T]

A wye would be best, which is a vee with a leg. You get tremendous torque right off the bottom of the throttle. You do end up gasping for air at high rpm. But with these heavy trucks torque is what gets you there. A friend in high school had a 261 six in his 50 Chevy car, still had the one barrel carb with a tube under the carb. He could hook it up good enough to lift the front wheels a foot off the ground.

[Corts60]

Originally Posted by Fred T

A wye would be best, which is a vee with a leg. You get tremendous torque right off the bottom of the throttle. You do end up gasping for air at high rpm. But with these heavy trucks torque is what gets you there. A friend in high school had a 261 six in his 50 Chevy car, still had the one barrel carb with a tube under the carb. He could hook it up good enough to lift the front wheels a foot off the ground.

That's awesome! I'm hoping to gain a little torque.....I know this particular engine's peak torque is between 1200-1800 RPM's, and a factory 305 had about 250 LB FT. Maybe I'll even gain a little HP too since she only has 125.

When I pull the whole engine, I want to have a custom grind put on the cam so she gets a little thump, thump too!

[Joey~AP]

"Different" is freakin cool!


Have you checked how everthing matches up? Are you going to need to do any porting and polishing so that it all matches up?

Old hot rodder that I am kin too use to double stack spacers under the carb and put a wire mesh in betwixt the 2 spacers to atomize the fuel.

[Corts60]

Originally Posted by Joey~AP

"Different" is freakin cool!


Have you checked how everthing matches up? Are you going to need to do any porting and polishing so that it all matches up?

Old hot rodder that I am kin too use to double stack spacers under the carb and put a wire mesh in betwixt the 2 spacers to atomize the fuel.

Well, I'm pretty much learning as I go here......This will be my first dual carb set-up and, as far as i can read, it is the first time most anybody has seen dual carbs on a big block V-6.

I know that I definitely have room to port the vintage speed manifold to match the factory V-6 manifold, I don't think I will just yet because it's not like I'm trying to gain a 10th down the track ya know? So I figure just get 'er all bolted up and running before the car shows this summer and then when I pull the whole engine this winter, I'll match everything up nice and pretty.

[4dranch]

Have you decided on breathers yet?

[Corts60]

Originally Posted by 4dranch

Have you decided on breathers yet?

What do you think about this one 4d? I already know the set-up is going to be too tall to keep under the hood, even without the spacer, so I have a picture in my head that has this breather sticking just a little out of the hood, almost like a shaker....

[4dranch]

[QUOTE=Corts60;3246487]What do you think about this one 4d? I already know the set-up is going to be too tall to keep under the hood, even without the spacer, so I have a picture in my head that has this breather sticking just a little out of the hood, almost like a shaker....
[QUOTE]

very cool..

Does the adapter only come in that hiegth? if not what about a machine shop. have them make you one shorter.

and with you doing all this work I think something like this will show them off alittle more just my 2 cents..

[texanidiot25]

Chop the bottom of the T-manifold's flange off and weld on the adapter's intake flange?