TW97C1500

I watched that video and it seems that maybe if you want to be precise, what they are doing is "properly positioning the distributor", not "adjusting the timing" like you, I, and other pre-computer people think of it. So I say on yours, check that the plug wire ports on the cap are pointing straight out to the sides, then see what it does. (disclaimer about cam alignment applies) I guess in computer controlled engine lingo, the computer does vary the timing up and down, so when you look for "setting the timing" or "adjusting the timing" you get all sorts of answers saying you can't do it.

You know where you plug in a code scanner beneath the dash? What he's talking about is they make a little doohickey that plugs in there and communicates with a smartphone or tablet or laptop computer by Bluetooth (radio broadcasting / "wireless"). I've been told by a couple of mechanics I thought knew what they were talking about that you don't / can't adjust the timing on the 96-98 (holdover 99) Vortec engines. The distributor goes in and is either right or wrong. The computer fine tunes timing. Of course, now people post these Youtube videos of people adjusting it, so I guess those yahoos were wrong. edit: I was also told by one of both of those guys that the distributor has a little bump on the bottom of the mounting flange that goes into a hole in the block and that's where it is supposed to be. I have 2 distributors from bad motors I've bought and neither has a bump there. I don't recall if the blocks have a hole. Pretty much, the plug wire ports on the cap need to be pointing straight out to the sides. This assumes the cam is aligned the same as a factory original.

I don't know if you have to find a '90 or if any 88-94 will have parts that will work, but I would think you could find a junk truck with A/C for $500 or less and get all the parts you needed and swap them on to your truck. Yeah, you might have to get a new compressor or evaporator but you would be much, much less than $3000. Or maybe you can find a junkyard that will sell you all the stuff real cheap and not try to ask high prices for something stupid they will just scrap for 50 cents anyway.

I don't remember and can't find where this single brown wire from the firewall bulkhead connector goes. I had looked at another truck, a 96, and thought I had it, but when I got to mine, it won't connect there. The other one must have had some option mine doesn't.

When you have the oil pan off, measure the stroke. Don't quote me on this, I forget the exact numbers, but a 305 will be 3.06 (3-1/16") and a 350 will be 3.56 (3-9/16"). Maybe it is 2-15/16" for a 305 and 3-7/16" for a 350. Or maybe it is 1/32" either side of 3" and 3-1/2". Heck, duh, the easy way to say it is if the stroke is roughly 3" you have a 305. If it is roughly 3-1/2" you have a 350.

Rag Man, sounds like you have a 305 (5.0 liter) and not a 350 (5.7 liter). I've never actually looked at a 305 block, but all of the 350's I've seen have 5.7 cast on them. On the truck's radiator cross-support, is the sticker still there that shows the belt routing diagram? It should say 5.0L or 5.7L, well that would be what originally came in the truck, and the PO probably removed that if it said "5.0L". Maybe he just didn't know and thought all Vortec's were 350's. Even the V-6's had "Vortec" on the plastic breather box.