Quarter Mile Gear Selection

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BHB4408

BHB4408

BHB4408
Joined
Aug 29, 2022
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Edgewood, WA
I could use some advice from A-Body Racers. I building an A-Body Dodge Dart, with a 512 Stroker Kit, Trickflow 270 heads, Lightweight crank, .680 Roller Cam, Edelbrock Max Wedge Single Plane Intake, 1050 Carb, through a Pat Blais 727 Transmission and 5,000 converter, w/10" x 29" Slicks, 8 point Cage, Strip Car Only (just Bracket Racing, Retirement fun) at about 3,100 pounds wet.

I'm ordering a Strange S60 Rear End and Caltrac's. Strange doesn't have a 4.30 PRO Gear Set available anymore. They only have 4.10, 4.56 (and 4.88).

Which should I choose between the 4.10 or the 4.56?

Thank you for your advice!
 
BHB4408 said:
I could use some advice from A-Body Racers. I building an A-Body Dodge Dart, with a 512 Stroker Kit, Trickflow 270 heads, Lightweight crank, .680 Roller Cam, Edelbrock Max Wedge Single Plane Intake, 1050 Carb, through a Pat Blais 727 Transmission and 5,000 converter, w/10" x 29" Slicks, 8 point Cage, Strip Car Only (just Bracket Racing, Retirement fun) at about 3,100 pounds wet.

I'm ordering a Strange S60 Rear End and Caltrac's. Strange doesn't have a 4.30 PRO Gear Set available anymore. They only have 4.10, 4.56 (and 4.88).

Which should I choose between the 4.10 or the 4.56?

Thank you for your advice!
Click to expand...
Depends on if you want to cross the stripe at over 7000 or under 6500.
I chose 4.10 with a 30.6 inch tall Hoosier
My small cam tf 240 headed 470 is making peak power at 58-5900 so I decided from there.
You'll have more I'm guessing and peak power will be 6400ish depending on cam.
 
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BHB4408 said:
I could use some advice from A-Body Racers. I building an A-Body Dodge Dart, with a 512 Stroker Kit, Trickflow 270 heads, Lightweight crank, .680 Roller Cam, Edelbrock Max Wedge Single Plane Intake, 1050 Carb, through a Pat Blais 727 Transmission and 5,000 converter, w/10" x 29" Slicks, 8 point Cage, Strip Car Only (just Bracket Racing, Retirement fun) at about 3,100 pounds wet.

I'm ordering a Strange S60 Rear End and Caltrac's. Strange doesn't have a 4.30 PRO Gear Set available anymore. They only have 4.10, 4.56 (and 4.88).

Which should I choose between the 4.10 or the 4.56?

Thank you for your advice!
Click to expand...

This is where a day on the dyno would pay massive dividends.
 
If you go with 4.56 and a 29.0 slick you'll be crossing the line at 7300-7600 rpm. How high you intend to Rev your motor should help you to answer your question
 
My 2 cents says to use the lowest numerical gear set you think the engine will pull. But I'm pretty conservative. I don't like spinnin stuff to the moon, because I'm always on a budget and if I blow something all to pieces, it's gonna be a long time comin before I can build something else. Plus, with a 512, you could run some impressive times with a 3.23 gear, so there's THAT. I'm sure you can stand more than that, it was just an example. I think I'd try a 4.10 and possibly even a 3.91......but with that tall tire, the 3.91 might not be enough.
 
I suggest the 4.10. Here's why:
A 512 stroker will have monster torque. The 4.10 will soften the hit a tad for better hookup. And as others noted, spinning that long stroke to 7500-ish would make me nervous.

But the real reason is I did this very thing with my avatar. Car had a 4.56 when purchased as a roller. Built a 408 for it and took it to the track. Tire is a 28" slick. Engine was out of breath at the 6700+ rpm it wanted to run in the 1/4 mile. So I switched to a 4.10. I was surprised...the 60' stayed the same, the 1/8 et stayed the same, but now I can run it out the back in the quarter at 6200 and not worry about it (as much lol). And the 1/4 et is faster.

You've got a LOT more motor than me so I think yours can easily handle the 4.10 with similar results!
 
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Sorry. 1/4 mile.

Cam Spec's; Bullet Custom Grind Roller .657, 275/282, 108 Lobe Separation.

I'm building the Rear End before the Engine's built, so I'm going to go with the 4.10 gear to play it safe, and it's nice that the S60 is easy to change gears if I need to in the future.

Wish the had the 4.30's, but sounds like they quit offering them in their S60 PRO gears.

Any other thoughts or advice is welcome and appreciated.
 
I've got there regular 430 gear set in my 10.0 second strip car with a spool. No problem after 4 years of clutch dumping.
 
I dont think having a pro gear would be required. Standard gear in that S60 can take a lot of abuse. Had that same setup years ago making right around 700 horse and using a brake quite often, never failed me, used 4.30 gears.
Hard to know what rpm the car will trap at without more info than what is thus far known. Slip, car weight, etc, etc.
But I would agree with others, 4.10 would definately be a very good place to start. Going to a 4.30 should raise your trap rpm roughly 250 or so more rpm over the 4.10’s.
 
Man i Loved my 4.30 gears in my old Daytona but I ran a 16-32 slick. I can’t even remember what RPM I went through the traps at hitting 160mph.
 
Agree with all the above, 4.10s, 95 %.
The 5%? If your stuff was mine, I might try 3.73s (if available in a dana).
There is no way you need 4.56, unless you were maybe running eighth mile ONLY. (And imo, still a maybe).
 
My buddy has a 493 built close to your build. He was running 4.10s with 28 in tires. Went to 3.73 to keep the rpms down at the stripe. Ran the same times.
 
33IMP said:
Agree with all the above, 4.10s, 95 %.
The 5%? If your stuff was mine, I might try 3.73s (if available in a dana).
There is no way you need 4.56, unless you were maybe running eighth mile ONLY. (And imo, still a maybe).
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I have 4.56 and 29.0 slicks in my bracket car and cross the 8th mile stripe at 6700 to 6800 rpm. I tried 1/4 with those gears and 32.0 tire and was running out of motor before the stripe. Rev limiter was set at 7500.
 
aaronk785 said:
My buddy has a 493 built close to your build. He was running 4.10s with 28 in tires. Went to 3.73 to keep the rpms down at the stripe. Ran the same times.
Click to expand...
That's been my experience with an iron head 440 too. I've had 4.30s, 4.11s and 3.91s in it, and the car doesn't care. No significant change in et or mph, just rpm at the lights. Gonna keep running the 3.91s.
My dumbass theory is that with the limits of a small block flowing head on a big block, rpm from steep gearing doesn't do much good.
 
I’ll be the first to ask:

How the heck do you build that big and elaborate of and engine and not know what gears your running? The whole system works as a package not ala-cart.

First thing my engine builder asked was gears, mt or auto and tire height and weight of the car. Just saying.
Syleng1
 
Syleng1 said:
I’ll be the first to ask:

How the heck do you build that big and elaborate of and engine and not know what gears your running? The whole system works as a package not ala-cart.

First thing my engine builder asked was gears, mt or auto and tire height and weight of the car. Just saying.
Syleng1
Click to expand...

Some know, some don’t, when in doubt, ask.
He’s asking.
 
Syleng1 said:
I’ll be the first to ask:

How the heck do you build that big and elaborate of and engine and not know what gears your running? The whole system works as a package not ala-cart.

First thing my engine builder asked was gears, mt or auto and tire height and weight of the car. Just saying.
Syleng1
Click to expand...
That's actually a pretty basic bracket engine. I did the same thing. Start somewhere, an engine just happens to be a great start to build a car around.
I was going to run 4.56 gears in mine but it turned out a 4.10 ended up being just fine after knowing exactly what my engine is capable of on the Dyno.
Now knowing that, I know what the ideal converter is, I know what weight I can build my car to and be at my desired E.T.
I knew what I had to do to build my transmission to last, I knew what wasn't going to work also.
I asked many people what gears I should run & most were wrong saying 4.56...dyno numbers say so.
 
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I'm not real smart on all of this stuff, but based on what you said about fun, retirement and bracket racing in the 1/4 mile VS 1/8th, I'd lean towards the most consistent ET setup you can get while making sure you don't blow it all to Hell. -More time at the strip and less time and money on rebuilding broken stuff. With all that torque, I'd think 3.91 or 4.10 gears would be the sweet spot. But like I said, I ain't schooled in racing.
Sounds like a great retirement though!
 
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