I guess it started a while ago with an occasional stumble from the '88 Vette.
About a week ago while playing in 2nd gear it stumbled badly and nearly died, as though starving for fuel.
Yesterday, with a minor stumble/surge, I had the fuel filter changed.
While warming it up last night it began to surge badly, up to over 1200rpm & down to 400rpm, even with slight accelerator pressure.
The scanner data showed closed loop, so the O2 was ok.
Unplugged the MAF and it still surged.
A mirror in front of the MAF showed that the sensor wire didn't glow red for 2sec after shut off (suspected the burn-off relay even though no codes).
Today, with the IAC unplugged (a tip from someone on the F-body forum) it still surged.
Though the part numbers differ slightly, with the MAF from the '86 IROC installed the Vette started right up and idled very smoothly; meanwhile the IROC, with the Vette MAF, shortly after startup surged and died as the Vette had.

Conclusions:
1) The Vette MAF is defective.
2) The time-honored test of unplugging the MAF didn't work for this case.
3) The scan tool information eliminated other possibilities.
4) It's realy handy to have another TPI car around.

I'm posting this scenario in hope that the info helps others isolate a MAF problem.

BTW, both MAFs are gutted and both intake systems have a ram-air pickup with K&N filters. The one in the Vette for about 2yrs now; the one in the IROC for about 4yrs now. So I don't attribute the failure to this mod.

Now the search is on for a "good price" on a MAF.

 

Check out the Well's high flow Maf at about $170. Address is posted on this board, do a search.

 

Z28DJP1987, thanks for the lead.

I found the Wells site and requested pricing/info for my application.