340 4 barrel and 340 6 barrel: were they really UNDERrated?
Having owned my '68 340 FS FB 727 3.55 rear Cuda since June 1969, I know a fair amount about how it ran. I purchased it with 17000 miles on it and the previous owner said it turned 13.7's at 102. I took the car to all the strips in the LA/LB area, especially OCIR, and turned in the 13.50's to 13.60's at 104+ all the time. With 3.55 gears, I went through the traps at about 6200 in second or shifted to 3rd at 5800 but turned the same times. With gears and better tires, it probably would have been in the 12's.
The Mopar Bible had a ET/Speed calculation and with the weight of the car and driver (i weighed 175 back then, not now), the calculations showed about 320 HP which is consistent with other reported values for a stock older high CR 340.
Being an A727 car, it shouldn't have had the 4sp cam, but the way the engine ran, that wouldn't have surprised me. The car was an earlier build of December 7, so how knows what they did back then.
All I can say is that a large number of 340 Dusters and Darts in SoCal at that time could also turn 13.70's to 13.90's if the driver knew what he was doing. So, my 340 was a little faster than most, but not by a lot.
I saved a bunch of timing slips from OCIR and attached a photo to show that this was real. No 0 to 60ft times back then, bummer.
Having owned my '68 340 FS FB 727 3.55 rear Cuda since June 1969, I know a fair amount about how it ran. I purchased it with 17000 miles on it and the previous owner said it turned 13.7's at 102. I took the car to all the strips in the LA/LB area, especially OCIR, and turned in the 13.50's to 13.60's at 104+ all the time. With 3.55 gears, I went through the traps at about 6200 in second or shifted to 3rd at 5800 but turned the same times. With gears and better tires, it probably would have been in the 12's.
The Mopar Bible had a ET/Speed calculation and with the weight of the car and driver (i weighed 175 back then, not now), the calculations showed about 320 HP which is consistent with other reported values for a stock older high CR 340.
Being an A727 car, it shouldn't have had the 4sp cam, but the way the engine ran, that wouldn't have surprised me. The car was an earlier build of December 7, so how knows what they did back then.
All I can say is that a large number of 340 Dusters and Darts in SoCal at that time could also turn 13.70's to 13.90's if the driver knew what he was doing. So, my 340 was a little faster than most, but not by a lot.
I saved a bunch of timing slips from OCIR and attached a photo to show that this was real. No 0 to 60ft times back then, bummer.