The earlier LT1's with the non vented Optispark system were the ones with issues. The later ones do not have the problems that the earlier ones had.LT1's are the best factory SBC but optispark isn't worth swapping to IMO. If you want an LT1 you are better off putting an LS coil on plug 24x ignition system or aftermarket like a megasquirt on unless you already have everything and it was cheap. The reason lt1's never took off like LS stuff did or traditional SBC's is they only came in lower production stuff like f bodies, vettes, and caprices, and regular opti failure scares the rest of the people away.
The LT1 itself is a solid platform but GM didnt really do the best with engine management or parts commonality.
I got it from Mallory Billet Aluminum back in 1998. Don't know if they exist anymore. Might be a challenge to find one now, I don't know.Roger, thanks for posting pics of your engine bay. I hadn't really considered using the Impala SS airbox and had mocked up the ecm in that location, but that's a great idea. Do you recall where you got the plug in the intake elbow for the silencer tube?