'Nuther day, 'Nuther problem...?

OK...so the '88 that I bought a few weeks ago has been running very well, better than expected for the $400 I paid for the truck with the exception of the oil pressure issue, which thus far I've addressed with an engine flush, filter and oil change (there was WAY too much oil in there) which has made a noticeable improvement. Tomorrow morning I am changing the sending unit.

Now, as I drove home from AutoZone the truck doesn't seem to want to shift until it almost red lines. In fact, once on the interstate it came within a hair of redlining before I backed off the accelerator. Also, when I shift it into drive from park the truck virtually lunges into gear.

I checked the tranny fluid and it's fine. The engine/drive train seems unusually loud, almost a groaning sound when it's approaching it's shift point. Any thoughts?

This won't explain the noise, but there is a posibility that your transmission has a shift kit in it.
That could cause the shift at high rpm's

This won't explain the noise, but there is a posibility that your transmission has a shift kit in it.
That could cause the shift at high rpm's

It's not a grinding noise or anything like that, it's hard to explain. It sounds the same as when the engine is cold - loud and groaning.

The shifts just started acting whacky yesterday. I've had the truck since the beginning of June and it hasn't had a problem shifting. The lunging forward from park is also new.

And...among other issues, I filled the gas tank on Thursday and it smells as if I poured the gas right into the passenger cabin. Strong smell of gasoline. I assume that I overfilled it and some may have spilled out the top...it isn't leaking or anything like that but boy is that annoying!

EDIT: I drove the truck for about a block today after replacing the oil sending unit and it was still acting whacky. As I pulled into a parking lot to turn around I noticed that the truck was bumping a little as I turned in a tight radius. That got me thinking that maybe, despite what the lights on the 4WD shift column said, it was STILL in 4WD Hi. So I put it in park and again moved the shifter (4WD) from 2WD to 4WD hi, then down to neutral and to 4WD Lo and back up to 2WD. I then reversed for about 100 feet. The problem has now gone away and the tranny is shifting beautifully again.

So, it looks as if I've driven it the last two days (less than 20 miles total) in 4WD Hi. Here's hoping I didn't screw it up come winter.

Live and learn, I suppose.

1.) Don't overfill your gas tank, only top it up to the nearest dollar after it kicks off.

2.) What is your idle rpms.