Which cam for a carbed 350 vortec?

[Miez]

Which cam should I get when rebuilding a 350 vortec with Edelbrock performer, Holley 600, hei inginition and planning rest to remain stock for street use.
A bit rough idle wouldn’t be an issue

Any recommendations?

 

[Bextreme04]

Which cam should I get when rebuilding a 350 vortec with Edelbrock performer, Holley 600, hei inginition and planning rest to remain stock for street use.
A bit rough idle wouldn’t be an issue

Any recommendations?

Is it a full L31 engine? Factory roller? Converting a stock flat tappet to roller?

If it is a factory Vortec L31 engine, you will be hard pressed to beat a Summit 8800 for value and usability.

https://www.gmt400.com/threads/summit-8800-cam-upgrade.66438/

 

[Ricko1966]

A bit of a rough idle wont be good for stock street use. Also wouldn't be a good match for Vortec heads. Or a good match for a dual plane with a 600 holley. The rough Idle is overlap,good for big end,not for low end. A street truck is going to be below 3500 rpm 99% of the time.Dual plane is for low end,600 Holley is for low end. Vortec heads will need mods to run over like .480 lift. and Vortec heads wouldnt be my choice for top end power (again that too much cam). I'll bow out here because IDK enough about aftermarket roller cams. I'd probably look at what GM is using in the HT 383 and stay somewhere near that. Looks like @Bextreme04 was typing while I was typing. Looks like he gave you a pretty good choice there.

 

[1lejohn]

A bit of a rough idle wont be good for stock street use. Also wouldn't be a good match for Vortec heads. Or a good match for a dual plane with a 600 holley. The rough Idle is overlap,good for big end,not for low end. A street truck is going to be below 3500 rpm 99% of the time.Dual plane is for low end,600 Holley is for low end. Vortec heads will need mods to run over like .480 lift. and Vortec heads wouldnt be my choice for top end power (again that too much cam). I'll bow out here because IDK enough about aftermarket roller cams. I'd probably look at what GM is using in the HT 383 and stay somewhere near that. Looks like @Bextreme04 was typing while I was typing. Looks like he gave you a pretty good choice there.

Thats the exact cam that I went with. It's the HT 383, Ramjet cam. The lift will play nice with the pressed in studs on the heads. I did use new springs along with the self-aligning roller tipped rockers. It will idle at 600, pulls to 5K rpms.

 

[1lejohn]

Pardon Our Interruption

Here is a link to the cam.

Pardon Our Interruption

The rocker arms. I can't think of the springs that I used.

 

[Rustisbest]

Crower 00409LM or similar. Can get into the higher lift stuff if you take care of the retainer to guide clearance.

 

[xm20k]

Pardon Our Interruption

Here is a link to the cam.

Pardon Our Interruption

The rocker arms. I can't think of the springs that I used.

This I wouldn't run anything much over this unless I had reworked or aftermarket heads that could handle the lift and had screw in rocker studs. I don't know at what point press in studs start to pull out, but I'd rather not find out. That duration and lobe separation won't idle rough it'll be pretty smooth.

That is if your block has all the provisions drilled and tapped to use the roller cam and its hardware.

 

[DoubleDingo]

I would run the old school 327/300hp camshaft. Oh wait, I did. Gen 1 SB, vortec heads, 327/300hp camshaft, great power improvement over stock.

 

[82scottsdale62]

In my obs I'm running a summit racing 8801 camshaft with aftermarket aluminum cylinder heads. The cam has a really smooth idle at 700rpm. the computer was commanding an idle of 500rpm, and it sounds pretty choppy down there. I cannot speak to the performanceof the cam yet as I don't have the computer tuned. Overall I think the 88xx series camshafts are a good option.You would have to do some modifications to the heads to run that cam. But you could probably run a summit 8800 without any problems

 

[DoubleDingo]

In my obs I'm running a summit racing 8801 camshaft with aftermarket aluminum cylinder heads. The cam has a really smooth idle at 700rpm. the computer was commanding an idle of 500rpm, and it sounds pretty choppy down there. I cannot speak to the performanceof the cam yet as I don't have the computer tuned. Overall I think the 88xx series camshafts are a good option.You would have to do some modifications to the heads to run that cam. But you could probably run a summit 8800 without any problems

Not sure if he has a computer to tune, but report back once you get yours setup.

 

[82scottsdale62]

Not sure if he has a computer to tune, but report back once you get yours setup.

I was just recommending the camshaft. I doubt his carb is computer controlled. I think that the 8800 cam would make an great street cam, with a smooth idle and decent fuel mileage (assuming he tunes the carb right) and have a very usable power band. The quality of my 8801 was amazing compared to the flat tappet cam I installed in the previous motor to that truck. I did a lot of research when trying to find a cam for my truck, and with him being limited to lift, and flow with stock heads, I think that the 8800 is what I would choose in his position. Another bonus is it only took summit two days to get the cam shipped delivered. Thats a lot faster than some of the other options out there.

Something else about the 88xx series cams is that they are made from 5150 billet steel! Not something you usually see in a cam at that price point

Here is a couple pictures of my 8801 bump stick

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And here is a video of the first fire up with that engine

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The engine had a vacuum leak from the tbi adapter. After fixing that and a little bit of tuning she idles just as smooth as the original tbi motor did stock

But that's just my two cents.

I have heard a lot of horror stories about the cheap quality of flat tappet cams nowadays and I personally will never run one again after having my brand new, freshly in stalled and broke in to manufacture specs flat tappet cam go flat within 20 miles

If the op goes with a roller cam, make sure to use a melonized distributor gear. Most roller cams are made of harder steel than flat tappet cams.

I apologize if this post is a mess. I am currently running on very, very little sleep

 

[82scottsdale62]

Here is another video. The exhaust clip at the tail pipe is after fixing the vacuum leak

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[Miez]

Thanks for the input so far. Looks like multiple options to go for.
Some extra info on the engine:
It’s casting 10243880 and all original at the moment. Bought it to rebuild and put in my ‘78 big 10.
I will be using stock heads and a 2116 Edelbrock performer intake with a Holley 600 (which is on my current 350 in the truck- just the carb).

Another question: there is no provision for installing a mechanical fuel pomp. Can I simply drill the two bolt holes and open the port to allow installing a fuel pump? Or does it need further mods to make that work?

 

[75gmck25]

Vortec heads have good flow and compression, so they respond well to a more agressive cam . The original cams are quite moderate (196/206 @ .050, etc.), so for a street vehicle it usually works well to upgrade to a cam that has up about 214-218 @ .050 duration. This duration used to be called an RV cam, and it works if you want more performance, a decent idle, and reasonable gas mileage. You also have to look at max lift, since stock Vortecs have limitations.

I used a Howard’s roller cam conversion in my SBC crate with 64cc aluminum heads and it has 213/217 @ .050. This combination has more power than the stock cam, and great low end torque to get the truck moving. It does not have the rump-rump idle that many seem to want, but makes a great daily driver and hauler.

I am using a 1985 vintage Quadrajet that I rebuilt with a kit from Cliff’s Perfomance, but it’s a lot of work (and money) to find a good Quadrajet and do a complete rebuild to the right specs. I would take a close look at using the Edelbrock AVS2, which seems to work well on an SBC with only a few tuning tweaks.

 

[75gmck25]

Another important item to check - is this really a ‘96 and up Vortec roller engine? Get the casting numbers off the heads, and also check for the roller block spider in the lifter valley. GM put the Vortec logo on many products, even a 6 cylinder engine, so make sure you have a genuine Vortec roller 350.