Moparts

Need some help with the Bonneville Daytona

Posted By: Lifsgrt

Need some help with the Bonneville Daytona - 05/27/20 07:43 PM

Hey, looking for a numerically lower than 2.76 8 3/4 gearset. I was told MOPAR made something in the 2.40 range at some point. Anybody have a line on a set? I have a 9" with 2.47s, but would sure like to keep it MOPAR.
I'm planning to be at Speed Week in August to break the Classic Production A engine Record.
Thanks
Posted By: RobR

Re: Need some help with the Bonneville Daytona - 05/27/20 08:02 PM

I think 2.71's are as low as it goes.
Posted By: MR_P_BODY

Re: Need some help with the Bonneville Daytona - 05/27/20 08:06 PM

Why dont you try a Gear Vendor in it
wave
Posted By: Lifsgrt

Re: Need some help with the Bonneville Daytona - 05/27/20 11:43 PM

$2800...I'm running out of $1000 bills for this project!
Posted By: Lifsgrt

Re: Need some help with the Bonneville Daytona - 05/27/20 11:44 PM

Dr Diff (Cass) says there were some in the 2.40 range way back.
Posted By: moparjohn

Re: Need some help with the Bonneville Daytona - 05/28/20 01:30 AM

Years ago I took apart a rear end and saved the gear ratio tag.
It was a 2:45 ratio so they were out there.
MJ

Attached picture APRIL 5676.JPG
Posted By: Cab_Burge

Re: Need some help with the Bonneville Daytona - 05/28/20 03:26 AM

I saw a 2.4? gear ratio in a 1967 Dodge R/T convertible or GTX convertible, CRS now blush in a 7 1/4 inch rear end, not sure if it was original or not shruggy
Posted By: polyspheric

Re: Need some help with the Bonneville Daytona - 05/28/20 01:07 PM

... and shorten the driveshaft
Posted By: Lifsgrt

Re: Need some help with the Bonneville Daytona - 05/28/20 03:43 PM

Thanks guys. If it wasn't at least a solid 8 3/4 I wouldn't risk it at 950hp. Probably have to roll with the 9".
Posted By: Pacnorthcuda

Re: Need some help with the Bonneville Daytona - 05/28/20 04:08 PM

Curiosity question.......about what top speed are you shooting for???
Posted By: Cab_Burge

Re: Need some help with the Bonneville Daytona - 05/29/20 06:12 AM

I have a 1940 Ford Tudor street rod I'm swapping the 8 inch Ford rear end out and putting in a 9 inch rear end out of a 1976/1979 Lincoln Versiale (SP)) that has 2.46 ratio maybe (by checking the ratio turning the pinion shaft until the ring gear makes one full revolution), I haven't taken them apart and counted the ring and pinion gear teeth to get the exact final ratio yet. I ended up with two third members that have the same ratio, one is a posi, and I don't think I want to use either one. I'm thinking a 3.4? something ratio with 28 inch tall tires with a AOD tranny. Both center sections have 28 spline axles
If you decided to do the Ford thing your welcome to the non posi third member for the shipping costs up
Posted By: Lifsgrt

Re: Need some help with the Bonneville Daytona - 05/31/20 02:43 AM

Current record for Classic Production A-engine class (440-500"ish) is 237.7mph, so not to be greedy, I'll settle for 238mph. My 9" with 2.47 gears should put me there at 7200rpm with 28" tires, assuming minimal tire slippage. Faster is better, bur a two pass average on two consecutive days in the same mile of 237.8mph will do it.
Posted By: Lifsgrt

Re: Need some help with the Bonneville Daytona - 05/31/20 02:46 AM

Thanks Cab, you'll need to come down if I can make it to Speed Week!
Posted By: Cab_Burge

Re: Need some help with the Bonneville Daytona - 05/31/20 04:32 PM

If things work out to the good maybe I'll be able to take you up on finally seeing racers run at Bonneville up luck
El Mirage dry lake racing was a lot different looking than the salt at Wendover up
Work on slicking that body up, reduce the wind friction up wrench grin
Good Luck up
Posted By: Cab_Burge

Re: Need some help with the Bonneville Daytona - 05/31/20 04:35 PM

Originally Posted by MR_P_BODY
Why dont you try a Gear Vendor in it
wave

It takes power to run any overdrive, direct drive doesn't work
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