somethings seriously wrong man. the 92 i just did a v8 swap in has a stock 87 marquis longblock, c4 and 3.73's will get a 3rd gear scratch at 65mph, 1st thru 2nd is worthless traction i'd be checkin little things like a vacuum leak or incorrect timing.
with a 5 speed you should be peelin the tires through atleast 4 gears with the 4.10's.
And I never really had a problem spinning or howling when the entire car was stock w/stock AOD, either, though I never really tried. It just happened once in a while.