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Discussion Starter · #1 ·
im about to purchase some large port vortecs 215cc intake and 65cc chambers for my 385 sbc, been shopping around and am seeing some different cast numbers just wondering which ones are the "best", im looking for the newly revised, i found these on jegs, are these the right ones? i would hate to spend the grand and come out with the wrong ones, also does anyone know if they come with accessery holes?


GM Performance #809-25534446




http://www.jegs.com/i/GM-Performance/809/25534446/10002/-1&parentProductId=991684
 

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Just my opinion, but if this is to be a street driver, I think it is too much intake port volume for a 383. I think you'll be disappointed. 195 would be about right, or even less, depending on cam.

I'm anxious for someone to bolt a set of these new Edelbrocks on a 383 and report back.....$950/pair retail....
http://www.edelbrock.com/automotive_new/misc/spotlight/e-street.shtml
 

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Discussion Starter · #4 ·
hmm.... why would the larger intake port be dissapointing? not enough fire off the line? i would be using the comp cams
#Xs274s rpm range=2000-6400 .501 lift
OR
Xs268s rpm range= 1600-6000 .488 lift
(both are solid hydra lifts)
 

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whatsamotor said:
hmm.... why would the larger intake port be dissapointing?
If you study fluid dynamics, you'll find that for any given amount of mixture flowing through a pipe, the smaller the pipe, the more velocity there is to the flow. The larger the pipe, the less velocity there is to the flow.

Given that the intake valve is only open for a fraction of a second at speed, it is a balancing act to have enough velocity to the fuel/air slug so that you pack the cylinder properly for max power. If you use a larger volume of port and the slug slows down enough, it could result in less cylinder packing while the intake valve is open and the motor could make less power.

Of course, all this is dependent on engine rpms. If I were going to build a 383 to spin to 8000, then most certainly I would want to use a head with a larger volume. But if I were building with hydraulic lifters that would be limited to just over 6000, I might want to use a head with smaller port volume to maximize velocity at the limit of rpm's I'd be using.
 

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I wouldn't even think of using a flat tappet hyd. cam with 215 intake ports... Its a bad combination.

Look over at RHS, they have a great head at a comprable price and is much more suited to yoru needs.

The biggest isn't always the best for the application...
 

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Discussion Starter · #7 ·
what about these vortecs... also, i was going to go with a solid cam not hydra my mistake

http://www.jegs.com/i/GM Performance/809/25534421/10002/-1?CT=999

Completely assembled, ready to bolt-on
185cc intake port
65cc exhaust port
Uses Fel-Pro #375-1470 exhaust gasket

Cast iron small runner or large runner heads
66cc combustion chamber, .450" deck thickness
No heat risers
Machined for 2.00"/1.55" valves
Hardened exhaust valve seats
0.530" max valve lift (without modifications)
Drilled and tapped for screw-in studs (7/16-14)
Dual bolt patterns for perimeter bolt and center bolt valve covers
Dual bolt patterns for both Vortec and early model intake manifolds (use early model P/N 10051103 or Vortec design P/N 12366573, P/N 12496820, P/N 12496821, P/N 12496822, or P/N 12499371
Use production intake gasket P/N 12529094 for Vortec intakes or dual bolt pattern intake gasket P/N 12497760 for either early model or Vortec design manifolds
Vortec logo (intake port roof), GM logo (intake port floors) & Bowtie logo (exhaust side) are cast-in
 

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Discussion Starter · #9 ·
those are bare though... these are assembled

those are 700$ for the assembled each.. i can get the assembled vortecs for 500 each, do you think these vortecs will be good with the cam choice?
 

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Now that you have said solid lifters, with the 274s or bigger(I would go 286 or bigger, a solid acts 8-10° smaller than a hydraulic of the same specs because of the lash), I would be back to looking at the 215 Vortecs.
 

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whatsamotor said:
those are bare though... these are assembled

those are 700$ for the assembled each.. i can get the assembled vortecs for 500 each, do you think these vortecs will be good with the cam choice?
No, you need to reread. The bare heads are priced Each. The assembled heads are $630 and $700 a pair.
 

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Discussion Starter · #12 ·
yeah.. im trying to stay away from too large of a stall seeing as the car will be spending alot of time on the street.. im thinkin the above 185intake vortecs with the XS274S will be good? or do you think the listed cam will work better with the 215cc intake?
 

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For your application I would go with RHS. If you had a 400+ci engine with a big hyd. roller bowtie Vortecs would look more promising, but at this level its hard to beat those RHS heads.

Do you already have a Vortec intake? OSme of the other RHS heads may fit a hair better but they are for standard intakes.
 

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Discussion Starter · #15 ·
no i dont have the intake yet but i think im still going to stick with the bowtie 185cc intake runner and a solid cam around .501 lift with a 2400 or so stall, not sure on gears yet but im thinkin 3:11's or 3:56's and a TH350 rebuilt.
 

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That would be a good combo with those heads as we have used many sets on some of our 358 engines we build, The do require a header for the D-shaped exhaust ports. The intake ports are more like 218 cc runners, The high port intake runners and D-shape exhaust ports are a win win situation

Tom and I use to work together and still deal alot back forth and here is a link to a pump gas daily driver http://www.3vperformance.com/streetperformance.html
 

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CNC BLOCKS NE said:
That would be a good combo with those heads as we have used many sets on some of our 358 engines we build, The do require a header for the D-shaped exhaust ports. The intake ports are more like 218 cc runners, The high port intake runners and D-shape exhaust ports are a win win situation

Tom and I use to work together and still deal alot back forth and here is a link to a pump gas daily driver http://www.3vperformance.com/streetperformance.html
I yield to experience. If CNC BLOCKS NE says they will work well, that's good enough for me. :thumbup:
 
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