Well, after many months I have almost finished the front suspension. It has been a litany of incorrect parts and learning new(old) things about the car. First, I was lucky to have a cousin in Vancouver with a business that had a warehouse in Washington state (and a US bank credit card) O'Reilly will not ship to Canada, nor will they accept credit cards based on non-US banks (That means my American Express from a canadian branch is not accepted) Once received, the local shop did a good job of replacing bushings on A-arms, king pins and bell crank. Now, a few words of caution.
If you have a 1" front sway bar, I have only found 2 sources for replacing the bushings. One is Dave Thibeault who, if I understood correctly from our conversation, make a bracket that fits the old Avanti support but accepts the new style of bushings which are too small for the old bracket. Essentially a smaller bracket. The other is Dan Booth (at Nostalgic) who sells bushings that fit the old bracket, but had been modified by Avanti after they stopped installing 1" sway bars and moved to 7/8" bars. Since Avanti had a large lot of the 1" hole bushings, they glued an insert into the hole to bring its size down. I went with Dan's bushings and ground out the insert to bring the hole back to 1" (dremel w/ steel grinder works slow but effective) It easily slide onto the sway bar (using plenty of liquid dish soap to smooth the bar). I am now waiting on a refund for the "wrong external sized" bushings I mailed back to "Avanti International Inc." over a month ago
Second word of caution: Any aftermarket front shock is NOT going to fit. DO NOT believe RockAuto when they advertise their replacement shocks for any pre-86 Avanti. Those shocks ALL have a 3" long base plate (end to end) while the centers of the two stove bolts that hold them to the lower A-arm are 3.5" apart (the Lark chassis). They cannot be secured. I had order KYB shocks and dealing with their support desk, I was told they have NO shocks with a wider plate on the bottom. "Gabriel" automatically acknowledged that I asked them about this issue and would get right back to me....but crickets. In the end, RockAuto acknowledged the problem, indicating that many other Avanti owners had complained about the same thing and offered me a refund (and paid return shipping) even though I was months over their return date policy. Given problems with returning parts across the border, I decided to build brackets for the lower supports. Using 3/16" flat steel, I cut eight 2" pieces from a 1" wide piece. I then gouged out a U shape from one side, approximately 1/4" deep in four of them. It is about 1" wide and tightly surrounds the flange of the shock. I next drilled out a 3/8" hole beyond the cutout and ground away the metal to join the two. The other 4 simply had a 3/8" hole drilled at one end. Now I will (and hopefully it will work having just finished the grinding an hour ago and still wanting to do a little more precision filling) attach the extensions to the 3/16" thick shock supports. and use the other single hole plate to act as a clamp, covering both the new extension and the base of the shock. It may be that there are suppliers that have front shocks with the wider support base, but I have been at this all summer and have gotten tired of the parts misunderstandings I had with some suppliers.
I strongly recommend Dan Booth at Nostalgic and am thank full to Dave Thibeault for suggesting him as an alternative to his product. I had easily ordered from Nostalgic years back but had mistakenly thought they had retired.