LT-1 What does LT stand for?

[Paul C.]

Anyone know what the LT in LT-1 stands for or is it just letters that stand for nothing.

[Joe L.]

Re: LT-1 What does LT stand for?

Anyone know what the LT in LT-1 stands for or is it just letters that stand for nothing.

Paul-----


"LT" is not an abbreviation for any word or words. In the GM system for regular production options (RPO's), engine RPO's usually begin with the alpha character "L". The remainder of the code is assigned more-or-less randomly from available sequences.

The codes are specific for certain year ranges and ARE RE-USED. In some cases, RPO codes that become "famous" in their own right are not re-used (e.g. Z-28). However, as I say, others are re-used. For example, "L-68" is the RPO used for 1967-69 400 hp 427 cid engines with 3X2. It was also used for certain 1985-91 2.5L 4 cylinder engines.

[Duke W.]

Re: LT-1 What does LT stand for?

When this alphanumeric RPO code system began in 1963, they usually consisted of one letter, a dash, and then a two digit number, like Z-06 and L-76, and the letter indicates the group; L for engines, M for transmissions, J for brakes, Z for special performance equipment packages, etc.

At some point in the late sixties, GM realized they would run out of codes for certain groups, so they began using two letters and one number, which vastly expanded the number of combinations. Thus LT-1.

At some later point the dash was eliminated, so when LT-1 was resused in the nineties it was written LT1.

Duke

[Terry M.]

Re: LT-1 What does LT stand for?

At some later point the dash was eliminated, so when LT-1 was resused in the nineties it was written LT1.

Duke

There is a whole long story about the dash/no dash. Of all the mention of LT1 in 1970 the only place the dash appeared was on the hood logo. For better or worse that became the defining mark.

Notice I am swimming upstream in my signature. I think they got it backwards.

Now they have gone and used ZR1, or is it ZR-1, for the third time.