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Cam selection sbc 400

3938 Views 9 Replies 6 Participants Last post by  Black408, 
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First off I have a small block 400 4 bolt main bored .40 over stock rods with speed pro hypereutectic pistons rated at 9.08:1 compression with 76cc heads. I have a set of the old double hump heads with the 2.02 valves, screw in studs and a 1.6 ratio roller rockers with springs good to a 525 lift. The crank is standard and has been polished. I doubt that it needs it but I have used ARP bolts through out the engine. I am considering 2 different cams both from lunati. The first is a 489/504 duration is 227/233 @50 and advertised is 268/276 performs from 1800-6200. The second is a 504/525 duration is 233/241 @50 and advertised is 276/284 performs from 2200-6400. I am using a pete jackson gear drive melling high volume oil pump and everything will be toopped off with a edelbrock performer rpm intake and a holley 750 carb. Transmission is a turbo 350 with a 2500 stall and 3:55 gears. Will be in a 69 chevelle street car that I will drive to the track, the car will not be driven daily so that is not an issue. In the future I will install a set of 3:73 gears and maybe a small 100 shot of nitrous. If you guys have any other suggestions as far as cams or anything that you would change please feel free to let me know. I would have went with different connecting rods and pistons however at this time that was all I could afford. Thanks for all the help.

Lee,:thumbsup:
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With either cam and 1.6 rockers it ain't gonna happen. .504 lift with 1.5's would be ok but with 1.6's it's .537 and the .525 is already too much and with the 1.6's puts you at .560. (or was that lift figured with the 1.6's ?)

Now at 9:1 compression those cams are big.
I was at 9.5:1 and ran a Comp 280H (230 @ .050 and .486 lift with 1.5's or .518 with 1.6's) cam in my 406. Stock home ported heades with 1.94/1.6 valves and ran a best of 13.5 @ 101.7 and 2.73 gears, swapped to 3.73's to a spinning 13.2 @ 103 in a 3450# Camaro.

Best of luck.
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9:1 with 76's is about 10:1 with 64's. Still slightly low for those 2 cams but do-able.
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