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Old 07-23-2014, 09:26 PM   #1
SLDPULR
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Cam and converter help

I have tried searching on this site and on other sites like the hotrodders forum about a good cam for my truck. All the info I can seem to find is on light weight cars or trucks with roller cam blocks. Could you guys please help!

Specs: 1969 c10 SWB, 350 bored .030 over with a skip white rotating assy. Probe flat top pistons,72cc pro comp heads 190cc runners, Turbo 350 trans, 373 gears, vic jr intake or rpm air gar (I have both), Block has been gone through and has a zero deck height. compression ratio of 9.9 to 1 when I put it in the calculator. 750 Holley DP carb.

The truck has a disc brake conversion so I need enough vacuum to run the disk brakes. This is not a daily driver and I don't mind running 93 or higher octane and I could care less about MPG. I am shooting for the highest HP with enough vacuum to run the brakes. Could you guys please give me your infinite wisdom and help me pick out the best cam and torque converter to compliment my build.

Thanks, Colt
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Old 07-23-2014, 09:51 PM   #2
engineer_gregh
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Re: Cam and converter help

I would call Comp Cams and ask for their advise. I used a high energy 268 in my 402. That worked ok for the brakes but I just added a Comp Cams vacuum canister and that helped. I caught it on Amazon for $11.98 just a couple of weeks ago, now its much higher.

Amazon.com: Competition Cams 5201 Vacuum... Amazon.com: Competition Cams 5201 Vacuum...
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Old 07-23-2014, 09:58 PM   #3
SLDPULR
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Re: Cam and converter help

Quote:
Originally Posted by engineer_gregh View Post
I would call Comp Cams and ask for their advise. I used a high energy 268 in my 402. That worked ok for the brakes but I just added a Comp Cams vacuum canister and that helped. I caught it on Amazon for $11.98 just a couple of weeks ago, now its much higher.

Amazon.com: Competition Cams 5201 Vacuum Canister, Zinc Plated and Polished: Automotive
I didnt think about a vacuum canister. Thanks for the info! I will keep comp cams in mind! Are they pretty friendly over there?
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Old 07-23-2014, 10:39 PM   #4
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Re: Cam and converter help

They are very helpful. They are headquartered in Memphis. Comp also owns Lunati cams but don't advertise it.
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Old 07-23-2014, 11:33 PM   #5
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Re: Cam and converter help

If in doubt, be conservative on cam selection. Big cams may mean big horsepower, but they also reduce usable torque needed for street driving. Big cams can also make it very tough to get fuel delivery calibrated accurately. I have a an old book on Holley carburetors by Dave Emanuel. This book was published over 30 years ago, but it holds true. It is a great reference for understanding four barrel carbs, but also has a well explained section on cam selection and all of the other changes that go along with it. I recommend this book to everyone reading this. Someone once told me that the word "carburetor" is a French term meaning "don't touch it". Until I got this book, I believed that.
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Old 07-24-2014, 02:49 AM   #6
Fitz
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Re: Cam and converter help

Since your truck isn't a daily driver you can be a bit more imaginative about camshafts, converters and brakes. When I went from a 350 to a big block the cam was already there, 258 degrees intake, 268 degrees exhaust and 0.610 lift. Overlap is about 90 degrees so the idle is choppy and the engine comes alive around 2800 rpm so that set the stall speed on the converter. Vacuum pressure in 'around town" driving was never more than 10 inches which just wouldn't run the booster. Rather than change camshafts, I added a vacuum pump from stainless steel brakes instead. Mounted it on the outside of the frame rail on the drivers side. Full brake pressure at idle or city street speeds no problem and I get to keep that lumpy exhaust note at idle.
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Old 07-24-2014, 07:08 PM   #7
SLDPULR
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Re: Cam and converter help

The vac canister is a great back up! I will call comps cams tomorrow and see what they say.
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