Here is my 1968 Valiant 100 4 door, it started out life with a 170 ci slant 6/auto. It was converted over to a 68 340 4bbl/4 speed with 3.23 sure grip 8.75 " rear, large bolt pattern all around with single piston later model disc brakes up front. This was done by a FABO member and I bought it from him a few years back.
That engine was leaking pretty bad from the rear main, so I swapped it out with a .030 over 340 I have had around as a spare engine for my 73 dart racecar.
Car has 68 340 HP exhaust manifolds with a 2.5" exhaust system with flowmasters, and sounds great. Car looks like grandma's old valiant but sounds like a street hemi on steroids!! I love just driving it around with the windows down and the radio off, the sweet rumble of nasty 340 engine!!!