Which Transmission to use?

kzcountry said

I have a 72 Demon and installing a slightly built 73 340 in the car. I am going with an auto for sure, my knees ain't what they used to be. Which one would you use 727, 904, 500, 518 ?? This will be a street car, not planning on any strip racing. Will be running a lot of 100 mile round trips. Thanks for your input.

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At the price of gas today, and looking into the future, you really do need to get the Rs down. 2400 is a good lower-limit number cuz you can just barely give her enough timing advance to make it worth the swap. At 2400 and cruising, she may like about 56 degrees. If you modify your Vcan to 22* then you can hit 24 on the mechanical.
To hit 2400 in loc-up, with 27s you need a rear gear of 2.965.
So the closest is 2.94s. But the starter gear is just 2.94 x 2.45=
7.20 so, with a stock TC, she will be a bit of a turd off the line.
A good starter gear is at least 7.90 (3.3 x 2.45)
to get 7.90 with a 2.94, you need a first gear of 2.69. The A999 has a 2.74 as do some A998s.
So there you go;
Get yourself a 2.74low-gear lock-up, 2.94s and a lil more stall than stock, which will depend a lot on your cam and cranking cylinder pressure. Easy Peasy.