63-67 tachometer

[Wayne M.]

Re: Time for a Summary..(rev. 1)

Tom --- Good synopsis on Duke's original format. One thing: 300 hp versions (and 250 hp, in years available) of all 5 mid-years had the redline starting at 5300 and going to 5500 (yellow zone 5000 to 5300). The '65 TIM & JG (rev 3) has this wrong (they say red starts at 5500). There is also some rumors that early L79's (350 hp) had the base engine tach, but my # 4835 had the 6000 - 6200 redline, so it must have been earlier than that. But then, the '65 manual also says all L79's had 60 lb oil gauges, yet my # 4835 had the 80 lb.

[Tom B.]

Re: Time for a Summary..(rev. 1a)

Thanks for the clarifications, Wayne. I remember my 66 L79 327/350 had the redline at 6000 too, but as for the earlier 327 engine options I really don't have a clue. I appreciate and thanks to Duke for providing the previous info on those. TBarr #24014

[Dave Wrzesinski]

Time for a Summary..(rev. 2)

Hi Guys. I already posted the 5500 red line for the 390hp 427 as 5000-5300 orange and 5300-5500 red AND already noted that the base SB engine used the same tach face. The JugGuide refers to 5000-5300Orange+5300-5500Red as a 5500 redline. I think the JugGuide could use a footnote. Of course, that may be my old edition with a problem. It still notes the wrong seat belts and fuel pump for late 66 cars.

[Wayne W.]

Re: Time for a Summary..(rev. 2)

I dont have any proof at this point but experience tells me that some 66-390 HP cars had 6000 redlines. Just keep that option open.

[Duke W.]

The bottom line

Jeez, I had no idea this thread would be so lengthly and controversial. One thing's for sure, solid lifter guys should observe the redline as valve float can cause risky contact between the pistons and valves, but you hydraulic lifter guys outta lighten up. Don't worry about the redline on the tach. Just rev it till the lifters collapse, and then shift the dang thang.

Duke

[Dave Wrzesinski]

Re: The bottom line

Hello Duke. The question was originally posted by a Swedish gentleman looking to buy a 66 without the original BB. He thought the tach was an indicator of whether the car was originally a BB car. I gave him twenty more ways to tell, but that was all in private Email while the originality tach war raged here.

I have a last thought to molify the 6000 rpm 390hp427 believers: Remember that the hydraulic lifter 427 was originally a 400hp engine at higher rpm. As first deliveries started, GM brass told Chevy to rate the engine at a lower HP at a lower rpm - the rest is history, but some have forgotten it. All 390hp engines are 400hp engines at 6000 rpm.