Switched to th400, what gear do I use?

[sackracing]

Now that I'm running a TH400, what rear gear should I use? I am going to run a 28 inch tire and will not spin it over 6500.

Thanks

 

[Otto J]

Leave the stock 3.42s in it

 

[rag231]

the same goes for a t-350? I had a 200 in it with 3.73's but I feel like I am pulling a lot of rpms going thru the traps. I need to find the calculator to figure my rpm's crossing the finish line.

 

[sackracing]

There's a calculator on mark williams' website

http://www.markwilliams.com/calculators.aspx