Given that the best thing PerformaBuilt transmissions does is take your money with ease without delivering a product for the amount you pay, I'm staying local and I recommend you do the same.

Dropped my Blazer off to a company in Michigan that knows old school transmissions.  In fact A & M transmissions is the destination for anyone in the state of Michigan for Powerglide 2speed trans and the older transmissions.  Of course they work on new transmissions as well.  I've been working with a guy named Jeff and he is very knowledgeable and very OCD on making sure its done right and it doesn't matter how long it takes.  Todays labor rates are around $99/hr

We discussed whether we are going to stick with the 700R4 and focus on why this transmission keeps burning up OR change to a 4L60e trans which is really the same as a 700R4 transmission.  In fact the only difference is the 4L60e has an 18-pin electronic connector above the passenger side pan rail vs the 700R4 doesn't have the 18-pin connector but does have the cable connection near the cooler lines on the passenger side.

700R4 PROS

• Less expensive than 4L60E – no expensive controller needed
• Easier to install with minimal wiring
• Popular upgrade support
• Fits most early chassis
• Transmission has cable speedometer output – no adapters needed

700R4 CONS

• Limited torque capacity with early transmissions
• TV cable is difficult to adjust for proper pressure and up-shifts
• Must use pressure gauge to set TV cable for proper part throttle up-shift
• Often requires custom TV cable bracket and connection on carburetor or EFI
• Custom WOT shift points require governor changes
• Limited to converter lock-up only in overdrive (4th gear)
• Needs special brake light switch to cut power to unlock converter when brake is applied
• May require additional low-vacuum switch to cut out converter lockup under heavy part-throttle load – and then may cycle back and forth – requiring additional delay relay

4L60E PROS

• Full and finite electronic control over all aspects of shift control, including WOT
• Easy changes to part-throttle shift points and line pressure
• Easy setup for desired converter lockup – can lock in third
• Can tune shift points from the interior – no need to crawl under the car
• Can buy EFI packages with transmission control as part of EFI – saves money
• Increased torque capacity with 4L65-70-75 versions
• LS engines can use the LS 4L60E – no adapters necessary
• Speedometer calibration is simple

4L60E CONS

• Most expensive – must add separate controller – can cost up to $1,200
• Needs a TPS input – must add with carburetor
• Requires adapter to run either electric speedometer or motor to spin cable speedometer
• Cooler lines use push-in clip connectors that often leak – should replace with a more traditional connector – AN or inverted flare

Told Jeff @ A & M Trans that my decision is to go to the 4l60e transmission.  He's now doing the research and gathering parts.