Upgrading the 410 Final Drive Ratio

[David C]

Hello John.

I'm nearing the end of an overdrive installation, keeping the original back axle ratio. Happy to share details if that helps.

If you are happy to trade acceleration for slightly lower cruising RPM a differential swap could well be worth a try. It shouldn't be too hard to find a 2.8 and you can upgrade to limited slip diff while you are at it.

Another option you might consider is finding an A999 transmission. This is non overdrive with lock up torque converter so would fit without the modification to crossmember and tunnel required by overdrive. Removing the slip would probably give a similar drop in revs as the diff swap and it would save plenty of fuel as well. You could go for broke and do both.

Please can you post pictures of how your air conditioning compressor is mounted? I am considering a Vintage Air system. Original Mopar air compressors were fitted above the alternator and I don't think will fit under the 410 bonnet. Sam Frost has kindly offered to help with details of what I believe is his factory installed system with the compressor mounted above the power steering pump.
I would like to compare all options before committing.