<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">looks like my chassis may be a 99..Looks like F53 did'nt come out till 99, even tho my coach says it was built in 98.. </div></BLOCKQUOTE>
The chassis VIN will identify the model year of the chassis, which may be different than the model year of the coach as a whole, as stated in the vehicle title. The chassis VIN might identify it as a year earlier, same year or sometimes even a year later!
Not sure what you meant when you said "...F53 did'nt come out till 99". The F53 chassis has been around far longer than that, but it didn't get the 4R100 tranny until 1999. Nor did the F-series trucks.
Here's a URL that will decode your VIN for you. The 10th digit is the model year, but I don't know for sure what letter represents 1998. This decoder will tell you everything that can be learned from a Ford VIN.
Ford VIN Decoder