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Good morning everyone, I’m building a 5.3 10:1 (lc9), 799 heads, Ls6 intake with a 4l60. It’s going in a 1939 Chevy, about 3000lbs. Looking for thoughts on a cam with these specs 218/227 .523/.523 112+3? Trying to find a good cruising cam without a valve spring change. Thank you.
Get the valve spring that matches the cam. In the end it will be worthwhile and springs for that cam would not be expensive. The last thing you want to run into is any sort of valve float issues, small cam or not.
Good morning everyone, I’m building a 5.3 10:1 (lc9), 799 heads, Ls6 intake with a 4l60. It’s going in a 1939 Chevy, about 3000lbs. Looking for thoughts on a cam with these specs 218/227 .523/.523 112+3? Trying to find a good cruising cam without a valve spring change. Thank you.
Check out Summit 8701R1 218/227, .522/.524,112+2. That is basically the Summit version of the GM Hot Cam with many refinements.
If you still have stock LC9 springs in there you will need to change springs. Stock springs can't handle anything over about .500.
If staying NA, I'd want more compression. At least 11.5 to 1 ideally 11.8 to 1. You can go as high as ~ 12.2 to 1 with 93
10 to 1 is pretty tame and leaves a lot on the table.
It’s just a sbe engine. I didn’t feel a need to change pistons. Although, maybe I’ll try and find a thinner head gasket. just to clarify the intent of the engine, I’m building this for my 75 year old dad. He isn’t looking for all of the horsepower, just building a cruiser. Looking for good manners, fuel economy, reliability and with a little more aggressive idle. Thank you
It’s just a sbe engine. I didn’t feel a need to change pistons. Although, maybe I’ll try and find a thinner head gasket. just to clarify the intent of the engine, I’m building this for my 75 year old dad. He isn’t looking for all of the horsepower, just building a cruiser. Looking for good manners, fuel economy, reliability and with a little more aggressive idle. Thank you
Then leave the compression where it is. With the lower dynamic compression from the cam, you should even be able to use 87 regular gas. Keep it simpler for us older guys...
It’s just a sbe engine. I didn’t feel a need to change pistons. Although, maybe I’ll try and find a thinner head gasket. just to clarify the intent of the engine, I’m building this for my 75 year old dad. He isn’t looking for all of the horsepower, just building a cruiser. Looking for good manners, fuel economy, reliability and with a little more aggressive idle. Thank you
The BTR "Truck Norris" camshaft would be a good choice.
Then leave the compression where it is. With the lower dynamic compression from the cam, you should even be able to use 87 regular gas. Keep it simpler for us older guys...
I TOTALLY AGREE on leaving the compression where it is. If OP insists on a bit more compression, maybe a 010" thinner head gasket. Sure, he could go a lot more rad, like some posts said, like 11.5-12.0:1. But you're close to the ragged edge on 93 octane when running a small cam, and Premium isn't getting any cheaper, or any higher in octane than 93, either. Also-Comp made, and may still make, a .560" lift, 224/224 on a 112° LSA, which would also be good. As Atsma said, don't change compression, or like I said, if you do, not much!!! Best of luck to you......
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Thoughts? 
