[superdutybob]

x-bird2:

My 74 LS2X intake is the same as the one Lloyd just sold. It has a casting date of E134 and as I stated earlier has a fully cast PN.

FTR: This is a great topic. I just love learning new stuff about the SD engine.

[x-bird2]

none of the 73s to my knowledge should/will have a full cast part number. no one that i know of has yet to appear with or prove the existence of a pre-emissions change SD equipped car. the original number was superseded by 494405 after "flunking" the emissions certification, which was prior to any of the cars being sold. the changes to the intake to make it comply meant that it had to be treated/identified as a new part that conformed to testing levels. for 73, there's a mix of either fully stamped (like mine), or partially stamped where the original "49" was not wiped off. When i started chasing after one of these in the early 90s (took me 'til 98 to come up with one i could afford), the amount of unknown and misinformation on them was quite a lot and much of it accepted as gospel. threads like these, multiple interviews with those involved by a variety of writers etc. have really brought a lot to light in the past ten years.--and some of it even from the insiders involved with the whole deal is conflicting and often a not too pleasant subject for them to discuss.

[74SDformula]

I decided to look at my car and this is what I found. My VIN is 121,XXX and has a build date of 12C.
Heads: G143 and F233
Block: A093
Intake: G193

I had the opportunity to look at another SD engine with a VIN of 123,XXX.
Heads: K282 and G143
Block: A093
Intake: K172 with the stamped 495107.

Both have numbers matching blocks and to the best of my knowledge have never had the heads/intake replaced.