Grill on 68-70' 1600 / Swapping Rear End

["Matthew Byrd" <matt.byrd@pinnaclepolymers.com>]

I have two quick questions..

I would like to know if the 68-70 1600's came with different grill than
the 2000's.  I know the 2000's have the "D" emblem.  Does the 1600's
have the older horizontal bars/grill?

I am looking at a few cars (1600's and 2000's) and I am finding a lot
more nice 1600's but I am concerned about there open road speed (or
RPM's).  I have heard that some people swap out the 1600's rear-end with
that of a 2000 (3.7:1).  Does this change really make that big of a
difference?

Thanks,

M.Byrd
(Soon to be 1600/2000 Owner)