Thread: Need advise on cam

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Hello, I'm new on here.
I am going to rebuild my 350 in my 69 c 10.
It's a 350 bored .060 over.
65cc iron heads with 2.02, 1.60 valves 165cc runners
Also have long tube headers with 2.5in dual exhaust
10.1 compression
Edelbrock performer intake
Edelbrock 600 cam carb
Th400 tranny with stock converter. Want to stay with stock converter.
3.08 rear gear, wanting to go to 3.43
I drive this truck alot, 60 miles a day when I take it to work.
I'm wanting as much power as I can get with this build.
This is what I'm going to work with, just need cam advise please. Flat tappet.
Thank you

You've painted yourself into a corner with the 10.0:1 static compression ratio. You'll need a cam that makes power from about 2000 to 5500 rpm's in order to put the intake closing point at the right place to coincide with the static compression ratio to make a Dynamic Compression Ratio that will be compatible with pump gas and make the power that you expect from your combination. A cam that begins making power at 2000 will need a torque converter that provides about a 500 rpm lead on the cam, so you will need a converter that begins stalling at 2500. I would recommend a 10" unit that is built specifically for this purpose, rather than a 12" unit with the fins bent over. I'd also recommend a 3.73 rear gear.

I have lots more to tell you, but I'll wait until you respond......

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Ok, would I be better off with 9.5 compression? 3.73 gear would kill me on the interstate. If I do change it would be 3.55 at 5he most. Probably stay at 3.08 for now.

This engine started with a cracked 882 head and stock cam. When I put different heads on I also replaced cam with a summit 1102. Duration at .5 is 204-214 I think. 112 lsa
Made a HUGE difference.
When I rebuild bottom end this winter I'm wanting to get more compression and bigger cam.
That's what this is all about.

That's just the way that a naturally-aspirated build works. More compression needs more cam which needs more gear and more converter. Keeping the static compression ratio down around 8.0:1 or 8.5:1 and bolting on a blower or turbo, you can make more power with less cam, less compression, less converter and less gear because you're forcing the mixture into the motor under higher artificial pressure rather than depending on natural atmospheric pressure to push it in. Even a modest 6 psi boost will increase power by at least 40% over naturally aspirated.

You could also make more power naturally aspirated by using better heads and more cubic inches. You could then keep the static compression ratio down, using less cam, gear and converter. Those production iron heads were designed for taking the family to the grocery store once a week, not for making the power that you're seeking. A set of Profiler 185 aluminum heads bolted to a 383 short block would make a heck of a difference. You could build her at 9.0:1 with a short cam and rip the tires off.

You're going to leave about 30 horsepower on the table with that short intake manifold and 600 will not be enough carburetor. Any 350 needs a 750 to make max power and a 383 will want an 800. Best intake manifold will be either a Weiand 8150 or an Edelbrock 7101. Do not use the Edelbrock Air Gap, or any other air gap manifold, as there have been cool weather drivability problems reported. Use the regular 7101 or the 8150. If you want to use a used intake manifold for less cost, you can also add a discontinued Holley 300-36 and Weiand 8014 to the list. I've seen them on craigslist, racing junk and other used parts sources.

Here are a couple of tutorials that I wrote several years ago that may help you.....

http://www.crankshaftcoalition.com/w..._compatibility

http://www.crankshaftcoalition.com/w...ips_and_tricks

http://www.crankshaftcoalition.com/w...op_dead_center

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Good read, thanks