[olddog]

I know nothing about the Megasquirt MS3-Pro. When I was first looking at all this, Megasquirt was offering a box of parts that you soldered together yourself or a huge step up in price to buy it assembled. Yet people were still loving it. The capability, access to software, universal sensor choices was claimed to be out of this world.

I was unaware Pro-M actually built a reversion resistant MAF. I do have a Pro-M MAF. They were universally called the best by all the tuners I was around.

Ed is correct. If you spend let's say a grand to go the Quarter Horse Chip route, eventually you will come to realize you delayed the inevitable by throwing your money away. At some point in the not so far future, your 30 yr old ECU full of capacitors that are drying out will fail. These ECU are getting harder to find. A few years back you could still buy re-manufactured units for $300 bucks. What all was replace in these during the re-manufacture process is questionable.

If you are not going to keep the car very long, maybe save the money. However the old technology may hurt the sale verses a modern new EFI. Typically you do not recover all the cost of a new anything. However you get to enjoy a much better easier to tune system. Trust me Binary Editor is no fun. On the other hand, if you plan to have this car 10 or 20 years from now, do you honestly think that 40 or 50 year old ECU will still be working?