Yeah, it's the taco ex-cab that stretched out to 120+ (as Volcom posted).
As for buying a 350 conversion... good luck! Be very careful when picking something like that up. $5500 seems a little steep, depending on the rest of the build and overall condition of the truck.
Some things to inspect closely:
motor mounts: make sure the welds look really good and the motor mounts look strong. If you're not sure what constitutes "good welds" or "strong motor mounts" take somebody else along that is familiar with complex mod's like a 350 conversion.
Engine placement: It should be back against the firewall to the extent that there should be evidence that they had to hammer the firewall back to fit the motor (distributor should be barely clearing it)
Exhaust: look for headers and check the routing of the exhaust the length of the chasis. Mine was done horribly and there was a cross over built (where the driver and passenger sides meet up) that went directly under the transmission drain plug. This means that each time I drained my tranny, I had to let it pour over the exhaust pipes, and you can imagine what happened when I got the exhaust hot the next few times.
Cooling: This will be the #1 issue with the SBC conversion. Look for a custom radiator setup (I researched and found that a 2-core alum radiator with 1" tubes was best when paired with a high flow electric fan).
Transmission choice: Ask and verify which transmision is behind the SBC. Stock toyota transmissions can go there (bell housing adapters are available) but most Toyota trannys weren't designed to take that kind of torque and will show it in abnormally short life spans. If it's an auto, look for the th350, if manual, nv4500. Those are your best bets (for $5500, I'd expect a top of the line tranny behind the SBC).
A poorly done SBC 350 conversion can/will be a nightmare to deal with down the road. Unless you like turning wrenches. If you're thinking about yanking it and putting a 22re or equiv in there, skip it and look for a different base to work from. You can do much better than $5500.
Oh, and welcome to the club! Be sure to post up if you have any more questions.
I'm outside your window watching you read this.