I want to change my diff

Blue · Post by **Blue** » Sat Jan 11, 14 1:08 am

Thing is we are all used to modern cars with 6 speed transmissions that can buzz along at 80mph @2500rpm, you can't do that on these old cars with only 3 gears if you still want tyre shedding performance.

MilesnMiles · Post by **MilesnMiles** » Sat Jan 11, 14 8:22 am

Back to the original posters question. I'm with Ivor, 3.55s make for a nice street gear. I found 3.91s a bear as I do lots of miles. Good fun hooning around Cornwall, but horrible driving 220 miles to Shakey.

You can also get 3.73 gears now.

I'd take up Pete's offer. Try 3.23 and then order the 3.55/3.73 you really want

Les Szabo · Post by **Les Szabo** » Sat Jan 11, 14 12:09 pm

It ALL boils down to what you wanna do with the car...if its cruising around at 2200rpm with the odd blast up the 1/4, then fit 3.55's and leave the engine alone but don't expect too much on the 1/4.

If you wanna 1/4 mile it more, and be quicker, leave the 4.10's in, fit taller rear tyres for the road, and spend some money on getting your engine to make power to 6000rpm so your motor won't run out of steam at the top end.

Or you can have both with 3.55's, leave the engine as is and hit it with a 125>150hp N20 shot for those quicker odd blasts down the 1/4.

Les

Blue · Post by **Blue** » Sat Jan 11, 14 3:34 pm

The other solution is a gear vendors overdrive, not cheap but allows optimum strip gearing with a sensible ratio for fast motorway use, the best of both worlds.

cadboy · Post by **cadboy** » Mon Jan 13, 14 7:28 am

Thanks guys after reading this I may not have to change my 3.91 just to get better motorway driving.

I have to look into wheel/tyre change to get the best.

Cheers

GJUK · Post by **GJUK** » Mon Jan 13, 14 3:21 pm

Very interesting guys Thank you.

Jon

Pete · Post by **Pete** » Mon Jan 13, 14 3:24 pm

Let us know what you decide....

GJUK · Post by **GJUK** » Mon Jan 13, 14 3:27 pm

I will probably leave it for now and try for taller tyres. The only thing I think might be and issue is the front lip of the rear arches that might catch (though that's another job I'd need doing!)

I want to cage the dart and sort out the interior first of all.

I've already spent too much on bits lol.

Mick · Post by **Mick** » Mon Jan 13, 14 10:14 pm

I dont know how much street driving you're planning on but 4.10 is a lot of gear, even with tall tyres. I personally, would opt for 3.55.
You'll have to give me your address and tel number again, as i 've been up to mansfield a few times recently and would like to see the car.
Mick

Les Szabo · Post by **Les Szabo** » Tue Jan 14, 14 2:44 pm

Just to give you an idea Jon, I ran 13.3 with the 340 cuda with 3.55's and 26" tall slicks and at the time, a super holeshot converter.....you should manage that?...if your happy with that or possibly you may just squeeze in the 12's, I don't know what you got in the motor? then you gotta go with the 3.55's. If you hit it with a 125hp N20 shot it'll put you in the low 12's or thereabouts....just something to think about.

Its all about buying the right parts for what you wanna do/achieve and not waste your money on stuff you don't necessarily need unless you got lots of folding!

If you hook up with Mick he'll give you some good advice...

Les

GJUK · Post by **GJUK** » Tue Jan 14, 14 3:09 pm

Mick wrote:I dont know how much street driving you're planning on but 4.10 is a lot of gear, even with tall tyres. I personally, would opt for 3.55.
You'll have to give me your address and tel number again, as i 've been up to mansfield a few times recently and would like to see the car.
Mick

Hi mate, you have a pm shortly.

Thanks.

Jon

GJUK · Post by **GJUK** » Tue Jan 14, 14 3:09 pm

Les Szabo wrote:Just to give you an idea Jon, I ran 13.3 with the 340 cuda with 3.55's and 26" tall slicks and at the time, a super holeshot converter.....you should manage that?...if your happy with that or possibly you may just squeeze in the 12's, I don't know what you got in the motor? then you gotta go with the 3.55's. If you hit it with a 125hp N20 shot it'll put you in the low 12's or thereabouts....just something to think about.

Its all about buying the right parts for what you wanna do/achieve and not waste your money on stuff you don't necessarily need unless you got lots of folding!

Les

Thank you

Jon