Be careful... the listing says ...with AN original 340... not with THE original 340... I betcha that isn't the original number matching engine. Probably isn't the original 4-speed either.
Most importantly, does it have the original camshaft in it. The 68 340 4 speed cars had a more aggressive cam than the auto cars. Many complained about how "lopey" it idled so they put the auto cam in the 4-speeds for 69 and later. THE 68 340 4-SPEED CAM @ 276/274 .444/.453 LIFT & 52° OVERLAP WAS THE BEST 340 CAM OFFERRED FROM THE FACTORY. Compared to the stock auto cam @ 268/276 .429/.444 Lift & 44° overlap.
Now on the disc brake upgrade. The 73 and later a-bodies used a 4 1/2" bolt pattern where the 72 and older models used the 4" bolt pattern for the wheels. If they didn't upgrade the rear axles to have 4 1/2" bolt pattern, then you will need 2 spares, one for each bolt pattern. If they upgraded the axles to 4 1/2" look at the axle flanges and make sure that if they were redirilled, they did not put 2 holes too close together.
Any modifications done that will have to be redone to bring to stock original condition should be subtracted from the price for the car. The car is worth the most money in original factory configuration.
To convert back to Kelsey-Hayes 4 piston disc brakes will cost around $1000.00. If it originally had disc brakes. Standard brakes on 68 340's was 10" drum.
