The 340 is the biggest POS V8 Chrysler ever made.

Corv8 kits are out there making the corvair a true mid engined V8 car with a near perfect 50/50 weight balance. If you get the late 65 up models with true IRS in the back and mid engine it with an LS7, and hang brembos and big meats at all 4 corners, you can have a dirt cheap super car. My pic is the 68-69 corsa 2 door hardtop for that conversion.
Actually a G body Gm car frame fits very nicely, under a 65 up Corvair body...