raposak

I posted this over at the carb section, but now am getting more just internal questions.

With the cam spec'd below, what would be a good valve spring to get. Most springs are either .550 lift or .600 lift. Do I go for .600?

Thank you for any insight.

Hello all, New here. I'm in the process of freshening up a LQ9 to put it in my 66 Lemans convertible. I want to go with a carb to keep that old school look. I have the following specs i'm considering. Please let me know if you see anything wrong with this setup. This is just a cruiser so not looking for anything crazy and like everyone, trying to do this on a tight budget. Might do upgrades in the future if money is available.

02 lq9
cam: 228/230 .571/.573 112
https://www.summitracing.com/parts/cca-cl54-428-11
keeping 317 heads and replacing springs
Holley 300-130bk intake
https://www.summitracing.com/parts/hly-300-130bk
carb: summit m2008
https://www.summitracing.com/parts/s...50vs/overview/

msd controller
TH400 trans
torque converter (undecided)

As for the carb, is it better to go with a vacuum or mechanical secondaries?

KCS

iTrader: (20)

I'd get a .600" lift spring, but that's really only a part of the big picture. I would check with someone at Comp to see what seat/open pressure they'd recommend for that cam. Chances are, a beehive spring would be ok at a minimum or a 400lbs open dual spring for a little peace of mind.

Darth_V8r

iTrader: (4)

make sure to upgrade your pushrods to at least 5/16 x 0.080" wall thickness to help prevent flexing and "pole-vaulting" due to the higher spring rates.

raposak

Great advice. I sent Comp cam the ?. I'm very new to engine builds so bare with me. Would the 5/16" push rods fit in factory 317 heads without modifying the opening?

Darth_V8r

iTrader: (4)

Yup. Very common upgrade.

raposak

which specs would be better for a 66 lemans with a th400 and 3.07 12bolt with stock 317 heads that will just be a cruiser

Specifications
RPM Range:
1300-6500
Valve Timing:
0.006
Duration:
265 Int
273 Exh
Lobe Separation:
112°
Duration @ .050" Lift:
215 Int
223 Exh
Intake Centerline:
107°
Valve Lift:
0.604
0.61
Lobe Lift:
0.355
0.359

Or

Specifications
RPM Range:
2200 to 7200
Valve Lash:
Valve Timing:
0.006
Duration:
281 Int
283 Exh
Lobe Separation:
112°
Duration @ .050" Lift:
228 Int
230 Exh
Intake Centerline:
110°
Valve Lift:
0.571 Int
0.573 Exh
Lobe Lift:
0.336
0.337

Darth_V8r

iTrader: (4)

For that gearing and that it will be a cruiser, I'd go with the smaller cam. When you start getting into 228+ durations, the car really starts to like more and more rear gear.

raposak

Well despite the great advice, I went with the larger cam. I'll swap out the gears after the restore to gain the best all around performance.

On that note, what TC stall would be recommended. I was thinking in the 3000 to 3200 rpm range.