90 SC light throttle sputter

Hello,
My 90 auto has a condition that has been getting worse with time over the past couple weeks. It has an intermittent sputter with light throttle and I have done a lot of searching but no definite answers. Independent a/f gauges are installed and the misfire is only occurring on the right side.
-I tried swapping o2 sensors today but the problem still remains. Recent headgasket replacement on the right, but the problem was there before the HG failed.
-I plan on checking for vac leaks tomorrow but would like to rule that out due to only misfiring on the right.
-Will also check the heat sink under the DIS but thats only about 2 yrs old.
-Sparkplugs were cleaned (blasted) for the HG replacement.

Any other Ideas? She runs great under heavy load and high RPMs so I would like to think the ignition system is alright. It almost sounds like theres a small backfire (through the exhaust not intake) when it misses. HB is secure and does not wobble.
Just trying to stay ahead of the game!
Thanks,
JJ

sputter update

Ran the engine today and pulled the MAF connector, no change in the way it runs. When it's unplugged the CEL illuminates, plug it back in and the light goes out. I'll search for MAF troubleshooting, any other input?
JJ

Spark plugs

Checked the TPS voltage today and all is ok. Swapped spark plugs between banks and the misfire followed to the left bank! Ofcourse I didn't note which plugs were in which cylinders but my spark plug tester confirmed 1 fouled plug. Picked up a set of plugs, will post results tomorrow. I have heard bad news about the Bosch plugs, and will have to agree, these are only about 1 year old. I picked up Motocraft platinums, hopefully these work out better.
JJ

bosch...bbooooooooo yes bad experiences like 20 years ago!

i'm betting either plugs or wires will cure it. bosch is a nono on these things. my 95 lx ate the insulator on one of them.

Plugs did it

Yup, new plugs did the trick. The salesman at autozone said they didnt carry the autolight 103's so I asked for his suggestions and he offered the Motocraft. Hopefully these last a little longer.
JJ