1 Lucky Texan

good job on the t'stat but, wonder if the prev. owner has monkeyed with some relays to keep the fans on or ???

was the intake air filter replaced? maybe it wasn't seated well where the tabs go in and high vacuum is making it whistle? have you inspected the brakes? Maybe the inner pad is dragging its squealer. (inner pads almost always wear more than outers) maybe a pebble between the rotor and brake shield.

in addition to the above suggestions; clean the MAF sensor (use proper cleaner for that) possible knock sensor problem too I guess.

yeah, knock sensor or Engine Temp Sensor , less likely, stuck open thermostat - but you didn't mention low temp gauge reading. if you have a scanner that can read freezefram data, you could try to force a CEL and read the FF dtat and look at the long term fuel trims.

could also be carbon buildup in the cylinders. Perhaps a SeaFoam treatment and knock sensor investigation to start?

can you run stickier tires? that will help. put the following on your list of candidates; Centric Posiquiet ceramic or (since you said you can tolerate a little dust) StopTech Street Performance (I've bought them from both RockAuto and KNS Brakes)

if you decide to drill, use a left-hand twist drill - might loosen the bolt as you drill, if not, you can still use the extractoer. or try one of these if the bolt isn't flush; http://www.amazon.com/Mayhew-29895-Stud-Extractor/dp/B000XSCDEA/ref=wl_it_dp_o_pdT1_S_nC?ie=UTF8&colid=IDEFQ97CY9SH&coliid=I3NLVZJOIHS95F http://www.amazon.com/Sunex-2-Inch-Piece-Metric-Puller/dp/B00063Z77W/ref=wl_it_dp_o_pC_S_nC?ie=UTF8&colid=IDEFQ97CY9SH&coliid=I2EAIANO5QBDJC http://www.amazon.com/Titan-Stud-Puller-Drive-Model/dp/B00265M8N4/ref=wl_it_dp_o_pdT1_S_nC?ie=UTF8&colid=IDEFQ97CY9SH&coliid=I1X03Z6XADUQ47

any CEL codes stored?

definitely check into disabling the airbag and or disconnecting the battery before digging in there.

if there are still bubbles in the radiator, there is either enough localized heating somewhere to boil the coolant, or there is a HG leak. maybe a shop with a tailpipe 'sniffer' could test for hydrocarbons in the radiator better than the chemical test? I dunno, sure seems frustrating and I hope you get it pinned down.

did any 98s have a rear LSD?

I believe you mentioned shifting to park/neutral solved the vibration? Many people have found that test to indicate a bad recently replaced axle.Not saying it couldn't be some other issue - or even solved by raising the idle speed. But, if it's a bad axle, rasing the idle speed will just mask the real problem at the expense of more fuel use. do a search, some complaints go back 12 years, known issue.

there are enough reports of people getting bad rebuilt alts, that taking it back for testing would be the first move I'd make.

that vibration description fits with bad axles quite well. Known issue with many rebuilt units and at least one post of a worn original soob axle I've read. I suppose a change in idle speed might help. try a search on the issue. If you can live with it, just drive, but the fix is likely a 'better' rebuilt or some new axle.

most likely, or there is a bad cable/ground or similar issue.

if you have active bubbling, those are likely combustion gasses from a bad HG. There is a chemical test you could use if you need confirmation.

cover plate on back of oil pump? cam seal? yeah, need to clean thoroughly and pin down the source.

I put the breaker bar end on the pad of the floor jack and pushed up with it. (car was on jacks) cheater should work too. I believe there's some type of sealant on the threads, dunno what the FSM recommends putting on there. Probably plenty of people have no problem reinstalling as-is. I used teflon pipe tape. Looking back, probably should have only used it on the drain plugs but, I'm not too concerned about it. Not ideal I know but...

I used a 1/2" breaker bar on 2 diffs so, 4 plugs total. I did have to use the floor jack to break 'em loose.

is there a dealer nearby? You might pay a coupla bucks more. The Tama may be OK, just not sure.

ouch!

that guy is a bicycle, moped, scooter and motorcycle maniac on American Pickers if you could get an email to him, I'm sure he'd know where you could get some help on info and maybe parts; http://antiquearchaeology.com/

they speak to that in the thread. Of course you can't drive our cars, or most cars, at wot at road speeds because you will accelerate. if no one cared about acceleration, you could use a 10-15 hp engine at wot to drive at a constant 55mph - and get great gas mileage.

I logged a 'run' at mostly 2k rpm in 4th gear. There's a stoplight in the session. Anyone here familiar with RR logs? I'm wondering also, is there any reasonable way this is related to my bad Secondary Air valves? That is, they rusted closed some time ago, I pulled the fuses and relay and killed the 15 or so codes with RR/ECUFlash. But, suppose they have moved or have corroded more? Could some kind of vapor buildup in them and detonate? To my knowledge, no one has reported a downside to treating the valves as I have, but.....