Posted By: 67Satty
3.91 or 4.10? Help Me Decide Please - 01/02/09 04:46 AM
'll be ordering up a center section in the next month or so for my '67 Satellite Street/Strip car.
The particulars of the motor are .040 over 440, TRW 2355's at zero deck, 9.75:1 compression, 238 @ .050, .534 lift hydraulic cam, unported 452 heads, Hooker 1 and 7/8" headers, Performer RPM, Holley 850 DP, FBO Ignition.
The trans has a 9.5" Dynamic Street/Strip converter, 4200 flash. I'll run 9X28 slicks at the strip. I'll be driving it to the strip, maybe 50 miles away. Other than that, I'll take it to cruise nights on weekends.
I'm not worried about RPMs on the highway, more worried about best ET at the strip. It will be raced on both 1/8 mile and 1/4 mile.
Thanks for any input, I'm trying to get back into this on a budget after a 20+ year hiatus.
Posted By: gch
Re: 3.91 or 4.10? Help Me Decide Please - 01/02/09 04:49 AM
Not that you asked but ported heads would go from
to
.
Posted By: Phil Saran
Re: 3.91 or 4.10? Help Me Decide Please - 01/02/09 04:55 AM
For the convertor you have and the rest of your combo go with the 4:10.
If you were to go with more convertor I would
say maybe a 4:30, still streetable, but not for
a 50 mile drive to the strip.
Just my
Posted By: BDS871Cuda
Re: 3.91 or 4.10? Help Me Decide Please - 01/02/09 05:26 AM
Sounds like a fun ride! I vote 4.10's
Posted By: sthemi
Re: 3.91 or 4.10? Help Me Decide Please - 01/02/09 06:01 AM
4:10s , you will like em..
Posted By: Anonymous
Re: 3.91 or 4.10? Help Me Decide Please - 01/02/09 06:55 AM
I bet i'm the only one that will say 3.90 but i think they will give you better top end, plus wit hall that tq that 440 will have with that stall the 3.90 may net better traction.
The only way i would go 4.10 is if i planned on some heads that flowed over 300 cfm. If you plan to stay with the stock heads for a while the 3.90 is what i would run.
Posted By: bonefish
Re: 3.91 or 4.10? Help Me Decide Please - 01/02/09 01:26 PM
410,i changed my street car from 430,s to 410,s and love it.the 430,s had alot more umph but were a little to much for my liking on the street.
Posted By: 440Jim
Re: 3.91 or 4.10? Help Me Decide Please - 01/02/09 01:55 PM
There will not be much change in performance at the track. If you hook it, the 4.10 may give you about 0.02 better sixty foot.
With your 28" tires and hydraulic cam, I would keep the finish line rpm to 6000. Use the on line calculators and your target mph. I really like 3.91 gears with 28" tires on street cars, but 4.10 might be slightly better on the track, but you will live with a couple hundred extra rpm driving on the street.
Posted By: Dr-Dave2
Re: 3.91 or 4.10? Help Me Decide Please - 01/02/09 04:03 PM
Posted By: Kevins493
Re: 3.91 or 4.10? Help Me Decide Please - 01/02/09 04:36 PM
We had almost the same combo in the 64 Plymouth. We ran 3.91's, but felt the 60ft and ET would be better with 4.10's, but with a 28" drag radial, the rpm was over 6000 at the finish line with the 3.91's and the same converter as you (drag radials don't grow so the finish line rpm is significantly higher) With stock heads (template ported), it ran out of steam over 5500.
Ran a best of 11.74 @ 114.
Posted By: dustergirl340
Re: 3.91 or 4.10? Help Me Decide Please - 01/02/09 04:47 PM
3.91's for my Duster is my personal limit for a street car. Mine does get driven on the freeway on occasion though. It gets bracket-raced on weekends during the season, and 3.91's made for the best consistency (doesn't sound like you care about that though if you are going for best ET).
Posted By: 383man
Re: 3.91 or 4.10? Help Me Decide Please - 01/03/09 01:43 AM
Thats very close to my 440 combo in my 63. I run 906 heads that I did some port work on myself. The bottom end is stock but I used KB quench dome pistons so I could get quench with the 906 heads and run on 92 pump at the 10.0 comp I built into it. But I run the solid MP .557 cam with the Holley Street Dominator intake and a 850 DP. I would like to get bigger headers as I use Hedman 1-3/4 tubes because they came with the car brand new in the box. I also use the same 9.5 Dynamic convertor that drives great on the street and flashes about 4200. I use 4.30's with 29 x 11.5 Hoosier QTP tires and I drive it on the highway all the time turning 3200 rpm at 60 mph. I shift by feel and it is right about 6200 when I shift and then I trap about 6300 and it still feels like it's still pulling. It has run 11.50's @ almost 117 mph at 3700 lbs and I drive it the 45 miles to my local track. I like the 4.10's with a 28" tire on a solid cam but you may run out of steam with the hydraulic cam. I would go for the 4.10's as you can always go to a 29" tire if it runs out of steam and needs it.
Good luck , Ron
Posted By: 67Satty
Re: 3.91 or 4.10? Help Me Decide Please - 01/04/09 01:50 AM
Thanks for all the replies everyone! Yeah, the unported iron heads are kinda my weak link but easy enough to replace with some budget aluminum heads in the future when I have the extra dough. If I had to do it all over again, I would've gone with a solid cam too. I've run a solid cam on a street car before and I don't remember it being that big a hassle.
Posted By: Streetwize
Re: 3.91 or 4.10? Help Me Decide Please - 01/04/09 05:06 PM
I'd go 4.10...it's only a ~5% difference and you can always opt to run a taller tire to knock it down to an Effective 3.91 if you were'nt 100% sold on it. Conversely If you didn't like the 3.91 I doubt you'd want to consider running a shorter tire to get an Effective 4.10.
, mainly do to finding out what you really want after you get the car done 
Another really good option is to install a 2:75 ratio low gear set in the trans now and leave the 4:10 rear gears in with the stocker style C.I. motor