Connecting rods

You didn't say what size /6 you have in the Dart. Size matters, when it comes to connecting rods at any rate. Kanter ( http://www.kanter.com ) has new ones for the 225 @ $30.90 per.

http://www.kanter.com

Doesn't say whether they are new or reconditioned. Not a bad price for new, but I would suggest calling to verify they are new. Also the application year is wrong. They are listing 1960-1983.
Yes it does make a difference what engine. 170, 198, and 225 all use different connecting rods, and the 1977 and newer 225 is also a different rod. I don't think there are any new 170 or 198 rods out there any longer. I haven't seen any in several years. 198 rods are as rare as hens teeth, even as used.