Hot Rods manifold recommendations

Hello folks, Mick here. I am getting a 350 chevy motor
ready for my project hot rod. It is a pretty hot motor with
a Lunati cam, good heads, moderate compression etc. I
have misplaced the cam card. I do remember it being .500
lift or so. It ran an Edebrock open manifold not a duel plane.
The motor ran very well. Now I want to use it on the street.
I understand the open plenum manifolds do not perform
well in street use? I do have an original early corvette 2x4
aluminum unit on hand. I did run an Edelbrock unit like this
on a 327 years ago with good results. I am wanting opinions
suggestions or information as to the viability of the corvette
unit for use with this motor. I am considering a cross ram
2x4 or a new duel plane unit. I am not opposed to opening
the carb base on the corvette unit if necessary. Thanks for any
recommendations.

 

We need more details, transmission, rear axle ratio, car weight, car type, rear tire size. What is the RPM range?


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Great results and good price on the Edelbrock performer rpm air gap manifold. I’ve put them on a handful of strong street engines and liked the low end throttle response and they’re not really a limiting factor at higher rpm

 

I 2nd that motion

 

While the vette intake might have been good for 283s, you would probably be better off with something that breathes better and you don't have to search for vintage wcfb's.

 

I really like the Edelbrock Performer RPM manifold. They may be the best street manifold available.

 

I have used both single plane and dual plane manifolds on the street.
All depends on what your willing to be comfortable with on the street.
I like both,,,,depends on the engine and driveline combo,,and your driving style.

Tommy

 

I’ve got a C3BX,,it is very similar to that one.

Also,,,,a PerformerRPM,,,,,,here is a side by side comparison.
The rpm is on the left,,,,although both are dual planes,,,,the rpm is a half inch taller.
Also,,,you can see the port runners are contoured a lot different.
The rpm runners are more narrow and taller,,,,where the C3BX runners are very wide and shorter in height.
I assume the rpm ,,even though it was a dual plane,,,it allowed somewhat higher flow for more power up high ?

Tommy

 

Thank you all. Good in formation to ponder. The motor is a 1969 LT1 as far as I can determine. I think the pistons are stock. Also pink paint on the rods. Ported and polished early straight plug fuel heads prepared by Mondello, rollerrockers pinned studs etc.Also a Isky rev kit Thatfeatures additional springs to help keep the rollers on the cam and allow for a bit lower valve spring pressure while still letting the motor rev pretty highly. It is going in a 40 ford coupe with a 1968 Muncie 4 speed.I will order a nine inch rear and have not determined a final gear ratio. If I can updateto a TKO or suchwith an over drive I can perhaps run stouter gear. Iam about to send the motor out for a re fresh. I may find the cam specks yet. If not Lunati may have records or the cam may be marked. I am not trying to get all that technical with the whole affair. I do intend to run the motor as is. Just want to get intake sorted out for street application.

 

In my experience, the single plane, 360 degree intake is designed for high rpm, basically wide open throttle, 3000-6500 rpm ranges. And provide that wonderful bog off idle on a street application. Unless of course you're running that stall converter that gets your rpm into that power band before it starts pulling. A dual plane design is lower rpm designed. And the rpm has a higher carb mounting surface. Has better off idle throttle response. But like somebody else said, rear gears? What rpm is this engine gonna see normally? All factors to consider. Plus like Mark mentioned, what do you want to see when you raise the hood? Good luck man, make Tommy sell you that rpm cheap

 

IMO... The Original intake LT-1, was the Best Street intake Ever made... Everyone copied it, For a reason... I had one on a stick Z/28, An was smart enough to pull it before I sold the car in the early 80's as a teenager... Still have it). An you could feel the difference at the upper end...

 

You know,,,,I wonder if GM designed that LT1/Z28 intake,,,,,,,hummmmmm.
However,,,you are right,,it is one of the best manifolds by far.

Tommy

 

I do hope to find a vintage intake that has provisions for the oil filler, breather tube. I am hoping to avoid ventilated valve covers. I will be using the same Mallory
cdi distributor I had on the motor after replacing the dual point. That was done to accommodate a cable driven tach. This little motor was run hard in a oval track racer. It ran well and was trouble free. I think a bit
of spirited street use will be fun. If it blows and it
may, I will be good with it. The motor has been in my shed for many years. Let it do what it was built for.
It will be the first time in a street car. I think it will be fun right up until it expires! Just like I hope to be! LOL

 

The actual LT-1 (note the dash) came out in 1970; 360 HP in the Z-28 Camaro and 370 HP in the Corvette. Same engine, but 10 HP difference in different cars; insurance reasons??? Years later, in the mid 90's the LT1 moniker came out again (note the NO dash this time), and with the front timing cover mounted Optispark distributor, fuel injection, and reverse flow cooling (Yuk!). But, whatever. I say go with an Edelbrock C4B or C4BX or a C3B or C3BX; I'm told the "X" was meant for the slightly raised ports of the 461 "X" heads, but who knows? The "notch" in the plenum divider of the C3B/C3BX was meant for the Holley 3 barrel carbs of the same era, but they work fine with a 4 barrel. And, some did't have the notch (???). I had one of the early C4B's with the actual 4 barrel mounting ports, like Moriarity's photo above, but like a dunce, I sold it. Like to find another. There's plenty of the older stuff out there still, but some of the prices people ask are a little ridiculous. Keep your eyes open, and talk them down on their price!
I am Butch/56sedandelivery.

 

IF UR gonna put in new gears/tranny anyway........keep what you got!!
ALL engines NEED a dual plane intake for street 'performance'(key word) is bologna.
Some stout SBF run better on the street with single plane/or they see no difference!
Now...........if UR gonna be driving in downtown Naw Lunz everyday maybe a dual plane with an A/T is your best bet but with an engine that starts its power range at 2500-3000RPM it won't take a milli second if your idle RPM is say 1000 RPM......coupled with a gear in the 3.73 to 4.10 range a open plenum intake is very doable.
6sally6

 

The motor was bought as an over the counter crate
unit in 1970. A lot of racers in these parts used them
for the basis of race motors during this era with considerable success.

 

Consider not modifying that Winters oem 2x4 intake, they are pretty valuable, you could sell it and pay for what you are lacking and still have money left over.
Not sure of the look you are after but no real reason to try for a " vintage" or HAMB era vibe if you are using the 69/up accessory bolt heads.
You already have what is considered to be one of most desirable small blocks Chevrolet ever built.
I would try to finish it with an oem LT-1 intake, it would "wow" anyone that knows what they are looking at.

 

How about a Weiand WCVSQ, dual plane 60s intake, a bit taller than a C3BX

 

Ran one of these with a stout 327 "Back in the Day" not cheap though. https://www.ebay.com/itm/Original-1...521286?hash=item2d00d58406:g:W40AAOSwGaVeEjb8

 

The accessory bolt hole in the heads are of no concern to me. I just prefer valve covers with no
pvc provisions. I enjoy the "traditional" aspects of a
build. However I am not bound by it. I would not use
an HEI distributor, but have no qualms using the Mallory cdi unit from the early seventies I have on
hand. Same for the muncie I took out of a 68 chevelle
station wagon. I am pursuing an intake like you mentioned.

 

Thanks for the part number. I have located a fellow in this area that has
a stash of vintage Chevy stuff. Including several intakes.
Being armed with the part number should be helpful.
There are quite a few older racers in this area holding
lots of "stuff" We did have a few local drag strips as well as oval tracks in the area. I do know many of
these fellows, and they know others. Half the fun of it
is the quest!

 

There would be no option for me if I had a dual quad manifold on hand. It’s a hot rod for Gods sake and nothing looks better than dual quads. So what if loose 2-10ths, are building a race car or something kool for the street especially if your not running a hood. Can all the shiney stuff too. Aluminum looks great clean....
PS: nothing sounds better than 8 barrels wide open either...

 

Without the draft tube port on the back of the block, non vented valve covers will make for a dirty oil fill vent area. 70 LT1 valve covers or
M/T covers would be a period choice.

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Where you will find a difference/problem on the early Vette 2x4 is the runners are going to be very small compared to the ports on your 350. It will run but it won't be optimal. You can take a dremmel and open the runners up tapered toward the plenum and that will help it breath a little better.

The intake that I really like for a moderate small block up to the 350/360 range is the L-79 with a 700 cfm (or highly modified 600) Holley. A 750 is easier to find and it will work just not as crisp as the 700.

I run a Holley Contender on my 355. I need more carb for it to be happy (on my mill) but it is a good street/strip intake. They still have the '60s high rise intake look. The down side is that they are not easy to find. The Weiand Stealth took its place which is also a good street strip intake. It has a smaller plenum than the Contender and is a lower profile intake (hence the smaller planum) but you can get by with a smaller carb with the Stealth.

 

I am noticing a discolored area on the top of that manifold. I wonder if it may be a crack repair of some sort? Perhaps epoxy or JB Weld. Makes me wary of
that unit. What do you think?

 

If a location is available on the intake, been drilling and tapping my intake manifolds under the distributor for a 5/8 hose nipple along with a baffle shield under the intake to replicate the draft tube port on the back of early blocks.
You would not want to do this on a expensive intake
I do this to run my favorite 327 valve covers without breathers

Engine is a 1970 block with Vortec heads in a 1964 Chevelle, Drilled and tapped the 5/8 hose nipple under the distributor along with drilling the Summit square bore intake for the oil fill tube. (not available on a Vortec intakes)
Looks stock enough for me and only the really knowledgeable sbc guys (like here on the hamb) can tell the difference.