[Cuda340]

The automakers do not care about the old cubic inch designations. Unfortunately, they seem to be married to the metric system. If Chrysler was going to use the old designation, it would have been this year with the introduction of the retro 6.1 (392 cu. inch) SRT Challenger.

Chrysler is trying to develop a high hp engine tht will be able to hold it own with the 400+ hp Camaro and the Shellby Mustang and not hurt it with future CAFE standards. Remember that Chrysler would prefer to sell its top-of-the-line engine in the SRT and not in some limited production model like the SS Challenger (quantity=profits).

The 6.5 must be significantly different from the 6.4 for it to be more acceptable of the MDS system.