BeerCan I know a guy that has a 99 350 and has put 3 trannys in....he never changes trans fluid, still doesn't ....oh well. At 300,000 miles I guess it doesn't owe you anything.
A few years ago a lady in town asked me if I would look at her transmission (98) because it wasn't acting right. I asked when was the last time she chained the fluid in it. She looked at me kinda funny and said .....never... lol I drained the tranny and about a quart of black gue came out...lol needless to say... out went the old and in went the new...transmission that is.