I have built tons of 340's and built tons of cars since the mid 70's. You really do not state any good particulars about the car. So I am going to assume when you ran the car was that with slicks or street tires. If not the converter you have is killing the 60ft. but allowing you not to spin the non slicks hard. Running 13.72 at 102 you should have a 1.90 something 60ft. With a 3.23 open rear and your 1800 converter your car must leave flat for about 30 to 40 ft. then come alive. Your converter is not letting the engine rev up into a good power band until 30 ft out. Here is a cheap remedy. You can get a cheap converter 2500 stall. 11" for $300 new. You need to curve the distributor for a lot better gains as stated by someone earlier. You will see a big difference in the motor and performance. When all that is done put a 1" carb aluminum spacer. All that for under $500. That's a good start at a cheap price. I had a great combo. I loved the old Direct Connection 521 Solid. I used 273 Adjustable rockers with longer adjusting screws. 30 over with stock comp. X heads with stock valves and a little bowl and gasket porting. Weiend 7545 Single plane with welded up heat risers. Ran better with a Holley Strip Dominator I might add back then. Holley 750 Dbl pumper with 90 jets rear and 86 frt. Direct Connection Racing cast iron electronic dist. Curved of course. Trans was a Joel's on Joy mild 727 with a 3500 B&M converter 10". Rear end was a 742 with 4.56 gears. In a 74 Dart Sport. Lots of little suspension tricks. Stock springs was a 360 Hipo car now on the east side of Detroit. It ran 11.60. later on a custom 904 tran by Joel's same motor and everything else. 10.95. What a difference. Motor was not that radical and that was way before any stroker kits. I still have that drive train been sitting since the 90's