1969 Engine Pad Numbers

[Scott Lawrence]

I have a 1969 Corvette L46 that I purchased from the first owner. The car is pretty much original except for the water pump and alternator. I have two questions regarding the numbers stamped onto the engine pad. First, the suffix code is HX indicating that the car is a 350/350 w/ 4 spd and A/C which is correct (I have a copy of the sticker and the original protect-o-plate). It is equiped w/ option K66 (transistor ignition) and is indicated on the sticker. I read in the NCRS Specifications Guide that a L46 4sp/AC/K66 car should have a suffix code of "GD." Is is possible that the block in this car was manufactured before they started using engine suffixes indicating the K66 option (manufacture date of car is 11/10/68)? Also, I have a large "154" stamped over a portion of the broadcast code? It's at least three times the size of the broadcast code font - does anyone know what this indicates? Any input would be much appreciated.

[Joe L.]

Re: 1969 Engine Pad Numbers

Scott----

In early 1969 (and definitely when your car was built) the K-66 distributor was installed at St. Louis. To do this, the St. Louis folks removed the standard distributor and installed the TI unit. The standard distributors were returned to the engine plant for re-use. So, for early 1969 PRODUCTION, all of the L-46 engines destined for cars with A/C would have had the "HX" suffix code.

In later 1969 PRODUCTION, the TI distributors were installed at the engine plant. This required that a different suffix code be used for engines destined for TI-equipped cars. So, for L-46 engines, the codes "GC" and "GD" were addded. If your car had been built after the changeover, it would have had the "GD" suffix code. But, it wasn't. The "HX" (A/C) and "HW" suffix codes continued to be used throughout the rest of the model year for engines without TI.

I don't know what the "154" stamping denotes. I strongly suspect that it was a machine shop/rebuilders stamping added to the engine when it was overhauled somewhere along the way. You might ask the original owner if the engine was ever rebuilt to confirm this possibility.