Correct Emission film Early 70' LT-1

[william J. #42757]

Now I'am lost, I have very early 70 LT-1 and need to apply a new correct emission film. GM web site list the film as early 70' part # 3989299 as the NCRS Judging manual for CL. The GM # 3989374 is stated as late 1970. Mine is very early 70' (Jan.13,) with correct block stamp as CTU. Do I need the 299 or 374 as correct?

[Jack H.]

Re: Correct Emission film Early 70' LT-1

Who stars in your Emission film? Wasn't it Clint Eastwood?

Seriously, I think you're talking about the emissions LABEL and the text of the current '70-72 Judging Guide is pretty clear:

"LT1/ZR1 350/370HP Code CL 3989299 up to at least s/n 5213

Code CT 3989374 beginning with at least s/n 6740"

So, the JG book is telling us the 'early' to 'late' transition comes in mid-March of 1970 production...

[Chuck S.]

Glad You Cleared That Up, Jack...

I wondered if I had been seriously studying 70 Corvettes for over fourteen years, and never heard of the "emissions film" on LT1s. LT1s are not my strong suite, and I was trying to place it...Very early p.c. owner training media?...Obscure "lick and a promise" emissions control device?... HUH??!! WHAT??!!