Nope! Raced many of 383 RR's with my 340 RR Never lost to one. Although 440's were hit and miss. Even beat my buddies 70 1/2 Z28 about 1/2 fender. The Mopar boys should be proud. If anyone doubts me I can take them for a ride in my HEAVY 69 Cuda 340 auto. and a 4.10 Dana 60' all steel and a mild steel 6 pt. but I do have S/S front seats in it. It's a 340 .030 over 10.5 and a 540/520 cam and ported X heads.