70 lt-1

**Lynn** · #1 08-22-2023, 04:54 PM

Corvette engine suffix codes for LT-1.

Books all show CTU and CTR

Both designations indicate manual trans and transistor ignition as well as 370 HP.

Can't be that one was with A.I.R. and one without, as all the 70 LT-1s were built with the smog pump. All LT-1s in 1970 were manual transmission.

So, what is the difference in the two suffix codes?

There is a third one (CTV) but that is clearly the ZR1.

**PeteLeathersac** · #2 08-22-2023, 05:32 PM

‘

Most listings show CTR but most say it was never used w/ production and all LT1’s built included CTU.
Being both stick designations, the extra suffix may’ve originally been planned for use w/ MA6 Dual-Disc clutch which was not offered w/ LT1 or for Trans. Ignition as an option which ended up being included w/ all cars?

~ Pete

.

**John Brown** · #3 08-22-2023, 06:06 PM

Quote:

Originally Posted by PeteLeathersac

‘

Most listings show CTR but most say it was never used w/ production and all LT1’s built included CTU.
Being both stick designations, the extra suffix may’ve originally been planned for use w/ MA6 Dual-Disc clutch which was not offered w/ LT1 or for Trans. Ignition as an option which ended up being included w/ all cars?

~ Pete

Just checked NCRS. It says;

A 'CTR' engine code (LT1 with T/I) has appeared in print, but records indicate it was not used, and is unverified.

**Lynn** · #4 08-22-2023, 07:14 PM

Makes sense.

**LT1vette** · #5 08-23-2023, 02:14 AM

One has power steering, one doesn't. I think it changed the size of the oil pan. Maybe a NCRS guy can jump in...

**Lynn** · #6 08-23-2023, 02:29 AM

Post 10 makes sense.

Ignore post #2.

https://www.corvetteforum.com/forums...on-70-lt1.html

**LT1vette** · #7 08-23-2023, 02:38 AM

Quote:

Originally Posted by LT1vette

One has power steering, one doesn't. I think it changed the size of the oil pan. Maybe a NCRS guy can jump in...

I was pretty sure, I had an LT1 for 27 years. But my memory on some of the details has been "faded" LOL

**turbojet427** · #8 08-23-2023, 12:43 PM

My 70 has CTK. June 70 build date, TI, no PS or PB.

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