1970-71 Nos Lt1

[Bob J.]

Re: 1970-71 Nos Lt1

Here is a couple more. Can anyone tell me what these inspection marks mean on the block?

Paul, the horizontal S in yellow crayon denotes "service".
I have the same S on NOS 327 blocks. Bob

[Dick W.]

Re: 1970-71 Nos Lt1

Tim, Thank you. I found it in a sub division of Denver on the local craigslist. It had been in the seller garage since the 70's sometime. It came from Burt Chevrolet, known as a high performance parts dealership.

About 30 years ago, a friend found a NOS '62 FI engine in the crate, NOS FI unit, and NOS T-10, all dated early '62. There are still a lot of treasures out there today, yer just gotta find them.

[Randy C.]

Re: 1970-71 Nos Lt1

Just a note that the casting date on the original block to my '71 Corvette CJK base engine is K260 (11/26/70) and it is a two-bolt main. I read somewhere in the long ago past that there were some base engine 4-bolt mains for model year '71 and that the CJK engine might be the one that had the 4-bolt mains, but it's not true in my case.

Nice find on the LT1 engine. Are you going to use it? I'd be severely tempted just to keep in "on display"!

Randy C.

[Paul Y.]

Re: 1970-71 Nos Lt1

Terry, I'm going to check that pan rail for letters and/or marks and post it here.

[Paul Y.]

Re: 1970-71 Nos Lt1

Dick, I'm happy to have found this one as I have wanted to build an LT1 for many years. Nothing beats brand new standard bore and standard crank for a starting place.

[Paul Y.]

Re: 1970-71 Nos Lt1

Joe, I guess that I am pleased because my 71 is a January car and though it is a base engine with AC, I am going to make it a bogus LT1 and bag the original engine for later. The 71 is a pretty good survivor car with all original matching numbers and dates, etc. and with a base engine, 4 speed, AC, PS, PB and I am the third owner. I have a set of 186 heads and I think I will put 2.5 inch exhaust manifolds on it with the rest of the 2.5 inch exhaust except for the choked down header pipes. I will try to use a spare set of midyear header pipes that are 2.5 inch. Then I will try to squeeze gas mileage out of it as that is my challenge. I like to drive them and I put a lot of road miles on them. The LT1 should make it a pretty fun driver.

[Paul Y.]

Re: 1970-71 Nos Lt1

Joe, still forged pistons though I take it? If so that will keep it simpler to build a manageable compression ration for pump gas.

[Paul Y.]

Re: 1970-71 Nos Lt1

Randy, I am going to put it in my 71 January build survivor type car and drive it although I do enjoy looking at it at this point.

[Terry M.]

Re: 1970-71 Nos Lt1

Just a note that the casting date on the original block to my '71 Corvette CJK base engine is K260 (11/26/70) and it is a two-bolt main. I read somewhere in the long ago past that there were some base engine 4-bolt mains for model year '71 and that the CJK engine might be the one that had the 4-bolt mains, but it's not true in my case.

Randy C.

Randy -- I don't want to drag this thread off topic, but the CJK code has had an aura around it since some early 1970s Chevrolet documents mistakenly listed it at 370 hp. Some read that and concluded it was an LT1 automatic in disguise rather than seeing that Chevrolet made a typo. Those who want an authentic LT1 automatic are doomed to drive a Camaro. And BTW those I have talked to who have driven the LT1/M40 say it is a real wicked ride. I am personally holding out for an L89/M40 -- but that is just me.