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415 SBC street/strip, Help with gear ratio?

8K views 16 replies 8 participants last post by  marks1972 
#1 ·
Hi,
Just looking for input/advice on gear ratio. I'm building a 72' Nova, approx 3400 lbs, 415 sbc mech. flat tappet cam 244/252 .516/.525 lift. Should be 485 hp @5,800 and 545 tq @3,800. Trans is a TH400 with 3400 rpm stall converter. It has 315/60/15 tires which are 30" tall. I'm ready to get gears for the Ford 9", I'm thinking like 3.73,3.90,4.10. It will mainly be street with some trips to the track. :confused:

Thanks
Mark
 
#6 ·
I'm looking at staying with the solid flat tappets. The costs of going with the roller cams/related parts start adding up pretty quick, and I'm trying to stay within a budget.

It is a Dart little "M" block with Dart iron eagle 230 heads. Realistically most of the time will be street fun with 2 or 3 trips to the track a year.
 
#7 ·
I don't usually run anything this small, but how about this Lunati?
Or give Rod a call at Isky and see what he recommends.

Street Strip Solid Cam - Chevrolet Small Block 280/288
These Solid Flat Tappet camshafts have been computer designed to deliver added performance without being too harsh on valve train components.
Solid, rough idle. Good Pro Street or Limited Sportsman cam for 355-406 cubic inch motors. Needs 2800-3500 RPM stall converter, headers, 10:1 compression ratio or better, and 4.10 gearing.

•Advertised Duration (Int/Exh): 280/288
•Duration @ .050 (Int/Exh): 247/255
•Gross Valve Lift (Int/Exh): .525/.540
•LSA/ICL: 106/100
•Valve Lash (Int/Exh): .026/.026
•RPM Range: 2800-7000
•Includes: Cam Only

Part Number: 401B1LUN

Jobber Price: $187.06
 
#8 ·
•Advertised Duration (Int/Exh): 280/288
•Duration @ .050 (Int/Exh): 247/255
•Gross Valve Lift (Int/Exh): .525/.540
•LSA/ICL: 106/100
•Valve Lash (Int/Exh): .026/.026
•RPM Range: 2800-7000
•Includes: Cam Only

Part Number: 401B1LUN

Jobber Price: $187.06
This is about the size of the cam I am running in my 383 with a 4/7 swap. Really love the upper RPM pull!!!
 
#11 ·
It does smooth out the motor and it does idle alot better in gear. Before the car would barely idle unless I turned up the idle to about 1200 rpms. I am running 11 to 1 comp in my 383. I can idle about 900 now with the 4/7 swap. I do have a 3500 stall. I havent had the car to the track yet. Still breaking in the motor. I will say it does through you into the seat and keeps you there all the way up to 6800 RPMS. It does feel better through out the RPM band as it seems the power curve is more throughout if that makes sense.
 
#12 ·
You said this was a street car you will only be taking to the track a couple times a year. I would definitely NOT go with a 4.10 rear gear...a 3.73 should be fine and keep your fuel ecomony in a decent range. If you aren't hitting the track but twice a year, all out performance definitely isn't in the scheme of things. There's really no reason for a big cam either (something else that will kill fuel economy and street driveability). It's all about compromise and if it's 99% street driving as you said your goal is, a mildly built engine would be what I would think would be your end point.
 
#13 ·
Mike,
You've got to remember he's running 30" tall tires. That would make the 4.10 actually have a better cruise RPM than a set of 3.73's with 26" tires.:yes:

I don't usually run anything this small, but how about this Lunati?
Or give Rod a call at Isky and see what he recommends.

Street Strip Solid Cam - Chevrolet Small Block 280/288
These Solid Flat Tappet camshafts have been computer designed to deliver added performance without being too harsh on valve train components.
Solid, rough idle. Good Pro Street or Limited Sportsman cam for 355-406 cubic inch motors. Needs 2800-3500 RPM stall converter, headers, 10:1 compression ratio or better, and 4.10 gearing.

•Advertised Duration (Int/Exh): 280/288
•Duration @ .050 (Int/Exh): 247/255
•Gross Valve Lift (Int/Exh): .525/.540
•LSA/ICL: 106/100
•Valve Lash (Int/Exh): .026/.026
•RPM Range: 2800-7000
•Includes: Cam Only

Part Number: 401B1LUN

Jobber Price: $187.06
I like that cam.
But I like this one too.:devil:
Lunati Voodoo #60142
249 / 257 @ .050"
.540” / .560” with 1.5 rockers
110 / 106 LSA/ICL
2800-7000

Both cams would like 1.6 rockers.
 
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