Left Handed Skyhook? - Orig Owner Story and Option

[69LM1]

OK,

Just bought another 70Z. Forest Green, green interior. The car got here (the last owner drove it from Atlanta to me here in New Orleans!) and for a change, actually looked better than in the photos. 66k miles, gobs and gobs of paperwork to back it up, and literally, not a scratch on her. Everything works, down to the clock and the cigarette lighter. Only negative thing is the heads/solid lifters were changed out at some point, everything else is stock but the headers. Original block/water pump/alt/distrib. Original TH400.

So, in the paperwork I see phone numbers from some of the previous owners. Guy I bought it from was the third owner and had it for 2 years. I start calling the previous owner once removed. He has a mechanics shop in Ithica, NY. Nice guy, says he bought the car from a friend, who bought the car new at the chevy dealership where he(first owner) worked as a mechanic.

I ask about why the solid lifters and heads were changed. He stated that the original owner got married and the wife complained about how "loud" the Z was, so he removed them. He bought the car when the orig owner and his wife divorced. BUT, he knows the guy that bought the heads from the original owner. That guy also has a repair shop in Ithica, NY. So he gives me that guys number with a promise to send him some pics. He owned the car for many years.

I call that shop, and the guy says the heads are long gone, BUT, just so happens, that the ORIGINAL OWNER IS AT THE SHOP! Man, what are the odds? So, the original owner and I start to chat. He also wants some pics. He confirms the heads/lifters/cam change. He starts reminising(sp) on how the forest green looked different in the paint chip then in person, and how he almost refused the car when he saw the color.

Now, for the LH Skyhook question:

He tells me that the car has a 70 only special option. Can't remember the name, but states that if you put the tranny in low1 for a drag race, floor it, the TH400 will "automatically" shift to low2 when the tach redlines. However, you still need to shift it to low3 at "Oh, around 90 or so". Claims the only thing that could beat him back in the day was a local 70 Cuda.
I have not heard of this and was wondering if he was pulling my leg. You know, the "Go get me a left handed skyhook" kind of thing. I promised to send him some pics, and he promised to look for the original set of keys that he thinks he still has.

So, here I am wondering if I had the B@ll's to try this on a 60k original car. What the heck? Right? If you can't have fun, what's the point.

I take her out on a deserted road about an hour ago, and from a stop, in L1, punch it. Sure enough, at 6300, she shifts to L2 on her own!

So, am I in the dark? What was this called, and was it standard on the 70 Z's, or an RPO option? Either way, it's Coooooolllll!

Rich

[Casey Marks]

This is a trait of 400's known as "blow shift". Basically, it is a fail-safe from the engine grenading itself. It is not an option, but a safety mechanism for the engine and trans. In fact, it can be seen in 700-4R's too. I was driving a buddy's 427 4x4 truck with a 700 in it, and just put it to the mat until the trans upshifted. Blow-shift is the "trans guy" term. Still cool tho ......

[sYc]

And if you stay in it, will do the same from 2nd to 3rd.

Some bracket racers never shift on there own, letting the trans do it for them, more consistant. But IMO, really takes the fun out of it. My theory is (not Rob's), shift when the beast quits pulling. Rob says that is what I tach is for.

[WILMASBOYL78]

Left handed sky-hook..sounds like something from boy scout camp....we used to send guys out for a left handed smoke shifter or my favorite, a "100ft of shoreline"

wilma

[69LM1]

[ QUOTE ]
And if you stay in it, will do the same from 2nd to 3rd.

[/ QUOTE ]

Have to try that one! Thanks Guys,

R

[Charley Lillard]

My understanding is 1970 was the first year for that in the Turbo 400's.

[Mr70]

It was and for ALL GM vehicles w/TH400,not just Chevy,regardless of their Horse Power.It also did help keep service replacements ("H" units) at bay.
I really like it behind the L-78.

[Musclecarkid]

Isn't this bang shift deal caused by the governor on the side of the trans just doing it's job? My TH400 did the same thing at about 5500rpms if left in low gear. Chirped the tires like a 4-speed. I know the Z28's and solid lifter big blocks had a different governor that shifted near 6500rpms.

[x Baldwin Motion]

my 04 5.3 (327?) silverado does that shift thing too. there is a switch on the shift lever for racing (has a picture of a trailer going up hill !!?) flick that on and get another 600 rpm's before the bang and chirp. hey, it's waranteed might as well stand on it !!

Chris

p.s. pass that tube of elbow grease and the light bulb repair kit.

[69LM1]

Here are some pics:
http://www.69lm1.com/70grnz

Man, a couple of friends were over last night, and I told them about this. Same reaction, naw, no way, bs. Took em for a ride one at a time, you should have seen the smiles. Ear to ear. Gotta try the 70 COPO now (it's a TH400 as well).

Rich