1966 Barracuda 273 Died!!! HELP

Well, the 340 will present some exhaust problems, as the early A stock exhaust manifolds have a smaller port than that of the heads of the 340. The drivers side manifold in an early A has that radius turn to clear the steering shaft and is the only manifold I know of that will clear the shaft. Headers will certainly facilitate this difference though!!

If you're thinking of using a 360, you will run across the difference in weighted flexplates needed to mate the motor to the trans, as the 360 is externally balanced. The snout of the torque converter is also smaller on the 273 so the converter will need to be changed if using any other crank than an early 273. The 360 will also need a rear sump oil pan.

Any LA motor will fit in just as the 273 does,,, it's all in the accesories. A later LA motor with the aluminum timing cover and brackets will cause you headaches due to the radiator inlet configuration, so a switch to the early waterpump and housing with your original brackets would solve that issue. Stuff like that you will need to tweak when your final combo is purchased!!

Lets get this problem solved first, I think with a little investigation and maybe nominal output of $$$ the car will be on the road again quickly!! Keep us updated, Geof