Best Gears for a 408 Stroker?

[halfafish]

Well I'm late to this party but in the interest of more info, here's the gear/speed/trans calculator I use. I like it a lot, as it's easy to change things up and see what that gets you. It comes preset with lots of stuff but you can manually enter any value you want and it still works.

Speed/Tire/RPM calculator

Too bad you already ordered 3.23 gears, I have a 489 case with 2.94 gears sitting in the shop.

 

[413]

A 650 carb is not big enough for this engine either.

 

[Dale Davies]

Wellll, that depends. Do not forget that 400 big blocks came with 2V carbs. For a low RPM street engine the 650 should be fine. Now if you build a more aggressive street engine or a more track engine, yes more carb is needed. The stipulation is that you do not get into fuel enrichment while in cruise mode.

 

[273]

Put a vacuum gauge on the car, do some full throttle runs is it's pulling a lot of vacuum probably go with a bigger carb. Make sure the breather isn't a restriction either.

 

[72DartGuy]

No worries! I wish I had an OD trans, but I’ve got a hand made 727 Billet stainless monster. I’ve got 3.23 gears and am getting the trans dialed in now. Just got her back on Tuesday, and the 408 is more than I expected. Took a year and a half just to find the parts! She’s finally getting dialed in and finished! With I could post a video! Thanks to everyone for the advice! I’ve created a Monster!

 

[Rat Bastid]

 

[Dale Davies]

No worries! I wish I had an OD trans, but I’ve got a hand made 727 Billet stainless monster. I’ve got 3.23 gears and am getting the trans dialed in now. Just got her back on Tuesday, and the 408 is more than I expected. Took a year and a half just to find the parts! She’s finally getting dialed in and finished! With I could post a video! Thanks to everyone for the advice! I’ve created a Monster!

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Looks like a good manifold and carb choice.

 

[RonsSwinger]

Hi guys, I have a 408 Stroker in my 72 Swinger. I gave a 489 rear end with 3:73 gears. I’m pushing 3500 RPM at 65mph. Not good! What’s the best gears for both street and freeway? 3:23’s or less? Thanks for the help!

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I have a Swinger with a 440 conversion currently running 355’s (28” tires). It runs around 3000 rpm At 60mph. I find the revs high for my liking and the cabin is loud for any distance driving. My ring and pinion are noisy so I have ordered a set of 3.23’s. I live in a rural area so all my driving is 50mph +. I hope to swap them in about 3 weeks. Car makes lots of power (460-500hp). I think I will be happy with them after running 355’s. (Time will tell). Ron D

 

[Dale Davies]

I have a Swinger with a 440 conversion currently running 355’s (28” tires). It runs around 3000 rpm At 60mph. I find the revs high for my liking and the cabin is loud for any distance driving. My ring and pinion are noisy so I have ordered a set of 3.23’s. I live in a rural area so all my driving is 50mph +. I hope to swap them in about 3 weeks. Car makes lots of power (460-500hp). I think I will be happy with them after running 355’s. (Time will tell). Ron D

I calculate the 3.23 gears will drop the highway RPM to about 2700. I would consider an overdrive transmission. With that 440 torque is not a problem to maintain your speed. I would be looking for cruise RPM of 1800 to 2200 for fuel economy, noise and wear.
My 2000 Dakota POS with the 3.9 noise maker is running right around 2000 RPM at about 62MPH. 400+ miles on the last tank of gas. I live about 8 miles out of town so back and forth with a trip to Edmonton and return making about half that miles.