Author Topic: '73 350 Setup  (Read 8273 times)

Offline mbvanhorn

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'73 350 Setup
« on: August 25, 2013, 11:52:42 PM »
HEy there, building my first C10 and would like some input/thoughts on my chioices.

I have looked around and am starting to plan my setup. Here's what I have so far..

Truck will be for cruising, meet-ups, and hopefully still be able to impress over a stock truck.
 I am just going to include the links to make it easier.

Already bored .030 over, dished pistons, 3spd, Holley 600

Voodoo Cam 262/268      http://www.summitracing.com/parts/lun-10120702lk/overview/

Summit Vortec Heads       http://www.summitracing.com/parts/sum-151124

Air Gap Intake                  http://www.summitracing.com/parts/edl-7516/overview/

Headers--Open to suggestions for vortec heads/fitment

Gears-- I know nothing about them


Also, do I need to upgrade springs? or are the ones that come with those heads ok?

Thanks,
Matt



Offline rich weyand

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Re: '73 350 Setup
« Reply #1 on: August 26, 2013, 12:22:09 AM »
The air-gap intake manifold is great as long as you use a thermostatic air cleaner.  If you plan on an open-element air cleaner (the two chrome pie plates setup), then don't use the air-gap intake manifold.  Here's why:

http://forum.73-87chevytrucks.com/smforum/index.php/topic,26459.msg220588.html#msg220588
http://forum.73-87chevytrucks.com/smforum/index.php/topic,26161.msg217465.html#msg217465
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline mbvanhorn

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Re: '73 350 Setup
« Reply #2 on: August 26, 2013, 12:50:41 AM »
I see, I guess I'll go with the Air Gap, NOT the RPM version, and copy your riser mod. What do you think of my cam/head choice?

Offline mbvanhorn

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Re: '73 350 Setup
« Reply #3 on: August 26, 2013, 01:20:52 AM »
Actually will the (NON - RPM) Air Gap Intake even fit the Vortec heads?

Offline rich weyand

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Re: '73 350 Setup
« Reply #4 on: August 26, 2013, 02:29:02 AM »
I haven't used the Voodoo cams or the Vortec heads, so I can't give a good opinion there.  That particular cam, though, has too much lift for stock Vortec heads.  Were you planning on modifying the heads to increase the retainer to seals clearance?
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline rich weyand

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Re: '73 350 Setup
« Reply #5 on: August 26, 2013, 02:57:57 AM »
Here's a sample discussion from another forum on Vortec heads and high-lift cams: http://www.hotrodders.com/forum/vortec-heads-max-lift-32857.html

Just google: Vortec maximum lift.

The 7516 Edelbrock manifold will fit the Vortec heads.  The 2601 is for the stock heads.

About the cam, I don't know about Voodoo cams as opposed to other company's, but I can speak to the cam specs.  Lunati says that's a great "4x4 and marine" cam, but lists the power range on that cam from 1400 to 5800 rpm.  And the lobe separation is 112*.  That sounds like a winder, not a lugger, to me.  You are putting this engine in a 5000 pound truck.  You want torque, not horsepower.  A torquer cam should have a lobe separation much tighter, like 108*, and shorter valve durations.  A 262/268 cam is going to have a much later intake valve closure and much earlier exhaust valve opening than you want for torque.  That indicates that cam is designed for high-rpm horsepower, where those numbers will help the engine breathe and give higher horsepower.  Great if you are circle racing.  But for street use, you spend almost all your time in the bottom half of the rpm range.

Look for a cam with 108 LSA, shorter duration, and a lower recommended rpm range if you want better street performance.  Don't fall for an old-tech grind, though.  Subtract the duration at .050 from the end-to-end duration.  You want a difference of 40-50 degrees.  Larger difference are characteristic of older grinds, while the newer computer-designed grinds get the valves off the seats much quicker, which makes it easier to maximize performance parameters.  On that score alone, you can see that the Lunati cam is a modern grind.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline Fairlane514

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Re: '73 350 Setup
« Reply #6 on: August 26, 2013, 06:22:23 AM »
The Summit Vortec heads can handle .520 lift right out of the box.

Offline rich weyand

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Re: '73 350 Setup
« Reply #7 on: August 26, 2013, 09:55:29 AM »
The Summit Vortec heads can handle .520 lift right out of the box.

Ah.  So the Summit versions come with the bosses cut down already?
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline Fairlane514

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Re: '73 350 Setup
« Reply #8 on: August 26, 2013, 10:27:14 PM »
Thats what they claim in the details of the description.

Offline mbvanhorn

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Re: '73 350 Setup
« Reply #9 on: August 27, 2013, 03:29:07 AM »

The 7516 Edelbrock manifold will fit the Vortec heads.  The 2601 is for the stock heads.


OK, I thought you said staty away from "RPM" (7516) in another post.

Offline mbvanhorn

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Re: '73 350 Setup
« Reply #10 on: August 27, 2013, 03:40:49 AM »
Rich, Does this Cam seem more appropriate then?  http://www.summitracing.com/parts/isk-cl201264/overview/make/chevrolet

Offline rich weyand

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Re: '73 350 Setup
« Reply #11 on: August 27, 2013, 10:19:06 AM »
The 7516 Edelbrock manifold will fit the Vortec heads.  The 2601 is for the stock heads.
OK, I thought you said staty away from "RPM" (7516) in another post.

Given a choice, yes.  High-rise manifolds increase horsepower a bit, while reducing torque a bit.  But Edelbrock has no standard-rise air-gap manifold for Vortec heads.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline rich weyand

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Re: '73 350 Setup
« Reply #12 on: August 27, 2013, 10:32:10 AM »
Rich, Does this Cam seem more appropriate then?  http://www.summitracing.com/parts/isk-cl201264/overview/make/chevrolet

No, that's worse.  Look at the operating range.  2000 rpm on up.  If you want a two-lane terror, you'll have great 50-90 passing times, but it will a stone brick off the line.  A stock truck will blow your doors off until it gets its breath at about 3000 rpm.  You can put a tall torque converter on it, then you just need to work out a bulk deal on replacement transmissions.

Somewhere along the line you seem to have been convinced that a high duration camshaft is better, a "bigger" cam.  For high-rpm horsepower, yes.  For a street machine, no.  Many of the hot rod boys (you know, '32 Deuces and triple-5 Chevys) use marine cams to get the fat torque curves that make a car fun to drive on the street.

Look at Comp 12-235-2, 12-231-2, 12-300-4, and 12-304-4, for example.  12-300-4 was my choice.  Sean Murphy at SMI recommended the 12-235-2 as being sort of like a ZZ4 without going to rollers.

Google my last name and 12-300-4, and you should see some threads here and elsewhere with long discussions about this.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline Fairlane514

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Re: '73 350 Setup
« Reply #13 on: August 27, 2013, 10:57:25 AM »
Check the Edlebrock 2116 Performer.....its what I am using.......from idle to 5500 rpm

Offline rich weyand

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Re: '73 350 Setup
« Reply #14 on: August 27, 2013, 11:07:02 AM »
The advantage of the air-gap manifolds is that the carburetor is always operating in its most desired temperature range.  Carburetion, as opposed to fuel injection, is a collection of compromises.  Various circuits, springs, air bleeds, and venturis in carburetors give you almost the right mixture under most conditions.  Fuelies have a computer monitoring the actual mixture constantly and continuously adjusting it to be a perfect mixture in all conditions.  Carburetors are open-loop systems, and fuelies are closed-loop systems.  With an air-gap manifold and thermostatic air cleaner, the carburetor is always running in a narrow temperature range: the carburetor is isolated from engine heat, and then heated by the induction air system to proper temperature.  This allows closer approximation to the correct mixture, because you can tune the carb to that narrow temperature range.  Not a big deal in moderate climates -- in Hawaii or Southern California, why bother? -- but in places where you have seasonal weather, it makes a huge difference.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift