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Discussion Starter #1
I read somewhere that the factory cam in a 351w is:

Stock 351
* Duration at .050 in.: 206 / 221
* Gross valve lift: 0.440 / 0.450 ???????
* Lobe separation: 115°

Is this right? I was looking at aftermarket cam specs and these [stock]numbers are stronger than some of the RV upgrade cams. What's the deal? For example, the Comp Cam 268HE runs 212/456. This is a pretty strong cam building power up to 5500, I can't see the stock cam spec'n at the numbers I mentioned. Somebody know if this is right?
 

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Discussion Starter #2
bump
 

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Discussion Starter #4
mid eighties
 

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it's Dan Five Oh
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that is the 351W HO (84-87) cam and the 351W EFI (88-91) cam.
 

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it's Dan Five Oh
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by the way what the hell is an RV cam? Old played out term that has no meaning today. That cam is a flat tappet cam, so although it's got a lot of lift (more on the exhaust than the Cobra R and Lightning), the ramp rate is really slow.
 

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Dan you realize this is over 3 years old? :toothless
 

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it's Dan Five Oh
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Not any more
 

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I don't get it. I had an Isky cam in a Pontiac 400 in my '79 Trans Am. Specs were 208 dur at 50, .435 lift w/ 1.5 rockers and 108 lobe separation. It had quite a rumble at idle and pulled strong to 5,000 rpms. Displacement eats cam. My '90 351W dosen't feel like it has near as much cam as my Pontiac did. I know the lobe separation has some to do with it, but that still sounds like a lot of cam for a 351 only making 210 horses. Are you sure those are the cam specs?
 

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it's Dan Five Oh
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Remember, the D9 and E7 heads don't flow worth anything compared to a small block Chevy head
 

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Makes sense. The Pontiac 400 is a big block, with large intake/exhaust runners. The heads I was using had 2.11 int/ 1.77 exh. valves too! Good old fashioned muscle!!!
 

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so nobody actually knows the specs then for a 1990 351 w sd hydraulic flat tappet cam then...its ok..im still looking my self. us speed density guys have to remember that mass air people w/ c6 and aod's dont have the troubles of e40d tranny with a speed density computer. so they would understand our anguish.nor do they have to ever research stuff like this any ways. the answer is out there. we just need to look els ware. maybe an after market cam maker has some old blueprints laying around
 

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Makes sense. The Pontiac 400 is a big block, with large intake/exhaust runners. The heads I was using had 2.11 int/ 1.77 exh. valves too! Good old fashioned muscle!!!
actually there is no Pontiac big block... the block has all the same dimensions, cept for bore and stroke from 326-455 cuin... some people think that this is a big block because of the large cuin and the fact that in 1977-1981 Pontiac shortened the deck height to make the 301... Big cuin in a lighter engines was one of the advantages PMD used to seperate themselves from the rest of the GM lineup... I believe that AMC did the same thing.. with their 265-401... not really sure about that though
 

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I don't get it. I had an Isky cam in a Pontiac 400 in my '79 Trans Am. Specs were 208 dur at 50, .435 lift w/ 1.5 rockers and 108 lobe separation. It had quite a rumble at idle and pulled strong to 5,000 rpms. Displacement eats cam. My '90 351W dosen't feel like it has near as much cam as my Pontiac did. I know the lobe separation has some to do with it, but that still sounds like a lot of cam for a 351 only making 210 horses. Are you sure those are the cam specs?
this is like saying my apple doesnt taste anything like my orange but they both had the same diameter... completely different engines... heads... gearing.. and on and on...
 
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