[Kudzupatch]

I have been digging into this as I am going to be replacing mine in the near future. My conclusion is, it is cheaper in the long run to buy a GM crate motor with a warranty then build one yourself. A quick run of the numbers in my area, with the machine work the cost is about even. And there is no warranty on my work.

If you are going to change anything in the engine, you need to change the 'tune'. I am going to put in the latter model Vortec and that by all means requires a tune to match the engine. Lots of horror stories of people builind engines with Vortec heads, cams, etc and they run worse than before but they are trying to run the stock tune on a modified engine. Typically they are trying to tune an engine by mail order because no one here is working with the OBD1 anymore. I had about decided to just buy a stock replacement engine.

Then I discovered Moates Ostrich, it replaces the chip in the computer and can be connected to most software and tuned like the new computers. Any tuner, if they are willing, could tune it for you. The idea is once it is right, you get someone to burn you a chip and replace the Ostrich, but many just keep in place.

This is the way I am going go. I will buying an Ostrich and a crate Vortec and use my TBI. If I have too, I will tune it myself but hoping to get one of the local guys to do it for me.