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3 speed auto vs 4 speed


Jack
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I have a 1981 2 door RR with a 3 speed torqueflite and a LT230 with 1:1.003 final.

Q: What problems will I cause in doing a swap from the 3 speed to a 4 speed ZF box?

Is an overdrive a better way to go to reduce revs at highway speeds?

Jack

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Dunno about prices where you are but an OD is almost certainly going to cost more than a 4-speed. I don't think the 4-speeds were any faster overall but they all ran behind a 1.222:1 transfer box so on yours it will end up faster in theory but may be over-geared.

Look at Ashcrofts site for gear ratios.

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I have a 1981 2 door RR with a 3 speed torqueflite and a LT230 with 1:1.003 final.

Q: What problems will I cause in doing a swap from the 3 speed to a 4 speed ZF box?

Is an overdrive a better way to go to reduce revs at highway speeds?

Jack

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I have an '80 2 door manual with OD and get about 2 litres per 100 klm better econnomy with it engaged, I also have a '93 with the ZF and was recently told by the local auto service shop that the Torqe Flight is almost indestructable compared to the ZF, so I guess it depends what use you have for the vehicle.

I do know that when a mate had an '81 with the Torqe Flight but no OD it was very sluggish until the revs were up then it was OK.

Hope this helps.

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I have an '80 2 door manual with OD and get about 2 litres per 100 klm better econnomy with it engaged, I also have a '93 with the ZF and was recently told by the local auto service shop that the Torqe Flight is almost indestructable compared to the ZF, so I guess it depends what use you have for the vehicle.

I do know that when a mate had an '81 with the Torqe Flight but no OD it was very sluggish until the revs were up then it was OK.

Hope this helps.

Thanks.

It seems that the 3 speed, although slow, can't be beraten for strength.

Just have to put up with it since the cost of conversion is about double what I paid for the RR in the first place.

Jack

Sydney.

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