Conversion: 1988 Chevrolet K5 Blazer 5.7L/700r4 to 2002 Tahoe 5.3L/4L60

I have been considering the pros and cons to do this project and I would really like any feedback at all.

I had let my K5 Blazer set around for the last couple of years barely driving it every 6 mths or so, this last time it had been about 8mths. I was taking it out making sure it would get my 17 yr old son to school since he wrecked his, and it just started losing compression and deteriorated very badly before I could get it somewhere. I know its in need of a complete rebuild, so I started pricing long blocks, and called an old friend to see if he had a block I could rebuild. He had just bought this 2002 Tahoe for scrape that had been hit by a deer and shot me a price 0f $350.00 for the 5.3L, ECM, and Transmission with 89,000 miles, and that he drove it around and decided to sell off the parts because everything ran great. I didn't know if I wanted the headache or not with a conversion, knowing it was different wiring. I asked around and found out it really wasn't that hard. There was mounting plates that would position everything just right, so no trial and fit. Next thing was the different wiring and upgraded systems with the newer 5.3L. I was told about this website and strongly advised it was more beneficial to do the swap. Better MPG, more HP, and the Harnesses could be made to just plug-n-play basically, from 1 system to the other.

I have some Questions and Concerns, if anyone could help, and any advise from anyone with experience with this conversion or similar would be greatly appreciated.

QUESTIONS
1. Will I be able to program the newer ECM to best benefit me for example: Increase MPG for everyday driving.

2. Can I void or omit certain systems and have the codes deleted from the ECM for the newer 5.3L without loss of performance or production. Example; Electronic Emissions, O2 sensors, Catalytic Converters, and any other non-essential systems to cut down on expensive parts for maintenance. I live in Arkansas and we do not have the strict emissions laws that other states have. (Here in Arkansas, if I owned the 2002 Tahoe and the Catalytic Converter had to be replaced we get it replaced with just straight pipe and have the codes deleted.)

3. What information or parts will I need to give or send to have the harness made?
Is it- what was it out of, what is it going into, and what is the motor, trans, and transfer case? Is there other information?
What is the Price to have this made?
Is it guaranteed or warranted? For How Long?
What is the Time frame normally from the Order date till Delivery date?


4. Would it be better to use the 4L60 Transmission or keep the 700r4(I've had nothing but trouble with the 700r4 transmission, rebuilt 3 times)?
What about the Transfer Case? Should I use the 1 from the Tahoe or keep the original 1 to the K5 blazer(which I trust more, cause I know it has been serviced regularly over it's life)? I was told both of them would bolt up without changing anything, just want to make sure.

5. Will there be any issues with Front and Rear Driveshafts; length or U-joints?

CONCERN

6. I'm sorry this is probably the wrong forum, but if anyone has knowledge or experience with this, please leave feedback.

I have always wanted to and I have inquired about upgrading older systems on the 1988, but was told "NO". I would like to put the rear disc brakes from the Tahoe onto the K5. Is it possible? Or will I need to just swap out the whole rear-end to do this? If so, will the front end change also, to keep the same gear ratio, or will it just be better and less headache to buy aftermarket disc brakes?

Are there any other concerns that I should be made aware of, or concerned with?
What are some of the most common problems associated with the 5.3L? Is there anything that I need to address on the motor before I install it?
Example: Cam-shaft sensor or Crank sensor- this seems to be the most common problems that I am familiar with.

With everything that I have learned over the last several days, I am very confident the reward will out-weigh the risk. Any suggestions, feedback, reference sites or materials, knowledge, or experience that anyone can give would be welcomed and appreciated.

Your friend is ofering you a great price for those parts, its not that hard, you can rework the harness for stand alone function then integrate it to your truck, you can do the tuning too, just need to purchase efilive and ask for help in this forum, probably you need to modify a lot of litle stuff, but its easy and it will be great with the ls engine, i have done a lot of those conversions by myself, alonee