1970 LS5 TI Ignition Coil...who's correct?

[Tom R.]

I've got a couple sources (including Amgwert's Vol 2 specs) that list the 1115272 coil for the 454/390 with TI but the 70-72 TIM&JG shows the 263 TI coil. Were both used or are one of the guides being updated? Thanks

[Chuck S.]

Re: 1970 LS5 TI Ignition Coil...who's correct?

Tom, I believe the 70-72 TIM&JG is correct. Status of updating 1968-1982 Spec Guide is unknown.

In the 70 AIM under option K66, Sheet A1, TI is shown as "Canceled" for 70 MY, but was available with optional engines. If you look at Sheet A1, the coil indicated for installation is 1115272. BUT, if you look in the "Revision Record" in the title block, Revision 1 is "Date: 6/30/69 Symbol: 1 1115263 RPO LS5, LS7 & LJ2 ADDED".

The way I read that is that 70 small block engines equipped with TI (L46s CTP,CTQ, and LT1s CTU,CTK) got the 272 coil, and big blocks (LS5s CRI,CRJ) got the 263 coil.

[Dave S.]

Re: 1970 LS5 TI Ignition Coil...who's correct?

Tom/Chuck,
I'm not sure if T.I. was ever really available with the LS-5 option in 1970 and most likely in 1971 as well. The backround on this is somewhat clouded but it is my recollection that T.I. was only available on mouse motors and was standard on all LT-1's. Maybe someone with more knowledge can chime in on this one.

[Chuck S.]

Re: 1970 LS5 TI Ignition Coil...who's correct?

Dave, until two weeks ago, I had never thought about ANY 70s having TI; then I learned LT1s had it, and then Tom suggested LS5s had it. Now I have done a little research, gained a little knowledge (hopefully accurate), and should probably be considered dangerous.

Anyway...the 68-82 Spec Guide and the Corvette Black Book both show TI available on all 70 engines except the base engine, and as you said, was standard on all LT1s. I'm not sure how the option was specified on the order form, and that would be interesting to know. It was apparently not ordered as K66 because that option was canceled before the 70 MY began. I also don't know what the experience is regarding actual installations observed on the judging field.

The TIM&JG also shows TI available on L46s, LT1s, and LS5s in 70, only on the LT1 and LS6 in 71, and not available at all in 72. That seems highly specific for a feature that didn't exist except on LT1s. If these three references are wrong, we have a ton of errors out there.

But, as you say, it would be good to hear from some owners and/or team leaders.

[Warren F.]

Re: 1970 LS5 TI Ignition Coil...who's correct?

Transistor Ignition system was part of the 1971 LS6 optioned Corvettes.

[Tom R.]

Re: 1970 LS5 TI Ignition Coil...who's correct?

Chuck:

Dave may have touched on something here because when you flip the TM page, it shows no reference for an 70 LS5 TI distributor...in contrast to the coil page which lists a TI coil for an LS5 TI application in 70.

[Terry M.]

Re: 1970 LS5 TI Ignition Coil...who's correct?

The coil listing in the 1970-72 TIM&JG is wrong. TI was not available in 1970 or 1971 separate from the LT1 or LS6.

[Chuck S.]

Re: 1970 LS5 TI Ignition Coil...who's correct?

Well, it made for interesting reading anyway. This confirms once again that you can only believe half of what you read.

I suppose that the reference books (68-82 Spec Guide, Corvette Black Book) used the Chevrolet literature without substantiation, and Chevrolet never followed through on their intentions, just as there are no N14 (side pipes), no LJ2 (3X2 carb), and no LS7. Er...At least I think that can be said...maybe. The difference in this case is that the references indicate, either directly or indirectly, that none of these options were ever produced

Terry, I suppose that means that the engine suffixes CTP, CTQ, CRI, and CRJ (TI equipped engines) were never used?

[Terry M.]

Re: 1970 LS5 TI Ignition Coil...who's correct?

"Terry, I suppose that means that the engine suffixes CTP, CTQ, CRI, and CRJ (TI equipped engines) were never used?"
Chuck,
That is our belief, but I am well aware that it is impossible to prove a negative. We have only been judging 1970-72s for 19 years, and none have showed up yet. Does that mean there were none? That uncertainty is why those codes are still listed in the beginning of the mechanical section, and why the coils are listed. There were no TI distributors for those applications listed in the information we received from Chevrolet back when the manual was produced. We simply printed what we had, and let the chips fall where they may. Can we say after almost 20 years that there were none?
The recent exhumation of convertible Z06s comes to mind of an example of the "never say never" school of thought on the subject of what Chevrolet might have built.

[Tom R.]

Re: 1970 LS5 TI Ignition Coil...who's correct?

Thanks Terry...I feel congruency now. I knew if we milked this long enough...you'd jump in!

[Chuck S.]

Tom, You're On Your Own Next Time...

I am leaving my bucket and stool in the barn. But, maybe you can help me with something unrelated that I have been wondering about:

"If a woodchuck could chuck wood, how much wood could a woodchuck chuck, if a woodchuck could chuck wood?"

[Dick W.]

Re: Tom, You're On Your Own Next Time...

Is that a Lyle, WA woodchuck, or a Cumberland, MD woodchuck? How much "Beast" has he had?

[Chuck S.]

Re: Tom, You're On Your Own Next Time...

Dick, determination of the boundries and dimensions of the problem variables are left to the investigator. The use of "Beast" or other mind expanding chemicals may be helpful but is not encouraged!