I don't have one and shift by ear. The car seems fairly consistent this way. I recall an interview with Herb McCandless where he said he was too busy to look at a tach back in the day! I'm GY3's neighbor and can hear the car well over a mile away - I'm confident he has no problem hearing it red line  LMAO! Rev limiter is at 6400 for a reason.... Test and tune on Kellogg Avenue. 
'63 Dodge 330
11.19 @ 121 mph
Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs.
10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.
| 
