I had a 2.76 gearset in my stock 7.25 rear axle which I liked for high freeway speed. I suped up the slant-6 to somewhere around 300 horse and put in a 8.75 rear with a 2.76 gearset, so I could get the high freeway speed and low rpm. I put a lower 1st gear ratio in the 904 trans to make up for the high rear end, but the 2nd & 3rd ratios are the same. Does anyone think this gearset will cause too low of rpms at freeway speed?

The wide ratio gearset for the 904 is:

1st: 2.74:1
2nd: 1.54:1
3rd: 1.00:1 (direct)

The standard ratio gearset for the 904 is:

1st: 2.45:1
2nd: 1.45:1
3rd: 1.00:1 (direct)

So, your first and second gear ratios are lower now than they were before.

We can't answer whether the RPMs will be too low on the highway without knowing about your engine build, particularly the camshaft and carburetor setup.

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