Hull did you try Hemming motor news there's usually and few company's in there that just specialize in correct, date, casting numbered, blocks and heads and so guys even restamp the block with the correct gm stamps, and if you do find a block for your vette, you want a cast date no later than 6 months of the build date of the car, if your going the numbers matching route... Sorry for the hijack with the pics, I just get excited when we start taking about my second passion and that's cars...

And Dave it don't matter so much about the letters on the front of block, unless you know were the car that motor was in it is, its the date code casting on the on the lip were the bell housing mounts to, that's going matter to guys looking for that block, if you got a late 68 or 71 date you better do your research before you sell it, because it was in a vette, and 427yenko, dana, nickey Camaro, chevelle, or nova, also the 70 and 71 454 vettes and chevelles and motion Camaros were 512 blocks also.. I've heard those blocks going for 10k or more..

I'm close geographically and can probably help you, I'm a Cigarette guy (5 so far) and over 300 Corvettes owned in the past. First, you are referencing the Tri-power 435. I've owned several. The 427 block is the same casting number for all '67 Vette big blocks. It's the stamping number that's different. If you are doing a 'matching numbers' engine, you are going to deck the block and restamp anyway. PM me, we can talk on the phone.