Anyone want to help pick a good gear for 1/8 mile racing for me?

Car is a '67 Satellite, weighs 3800 pounds with driver. Mild 440, hydrualic cam, Performer RPM intake, 850 DP, 1 and 7/8" headers, Dynamic 9.5, 3.91s, 27" tall tire. Best time so far 7.96.

Right now, I shift into third right before the stripe so not the best. I drive it to the track but I'm willing to put up with a lot for lower ET. Thanks!

Multiply the gear you finish in (1.45:1) by your current axle ratio to get 5.67:1.
Since your MPH will improve, and you need some safety, deduct 10%: 5.10:1.
4.89 looks like a possible.

Thanks for that! I was thinking of going from 3.91s to 4.30s. Do you think that would drop my ET by much?

Go with a 4.56 gear with a tall tire you can still drive it and race 1/8 mile. I ran 4.56s and 4.30s on street for years just plan on driving 60-65.which your supposed to do any way

Track run 26" tires or less in 1/8 mile

That's a good idea to just run taller tire for driving around on the street. I could put a 275/60-15 on it for driving on the street and then use my 27" tires for the track.

I found this forumula online also.

Tire Diameter x RPM / (336 x mph) = Gear Ratio

IE: 27 x 5500 / (336 x 90) = 5.13

I would really consider NOT running 5.12s or whatever on street without at least 31 + tall tires. After afew trips it will get old. Stick to the 4.30s or 4.56s you can live with the revs Small blocks can handle 3500-4000 for hours if cooling system is matched correctly.

No , there's no way I'd do 5.13s on the street. I just put that up there to show the formula.

For what it's worth to the conversation,,I changed from 4.89 to 5.13 in my car years ago. NO change ANYWHERE on the time slip.