wider rims on the RD250B/RD350;will a 1.85x18 w/ a 100/90 tire fit the front?

[grcamna3]

I want to fit one-step wider alloy rims(2.10?x18 Rr & 1.85x18 Fr)onto my 75' RD250B/350.
Do you know if a 1.85x18 w/ a 100/90x18 front tire will clear the front fender;if not as-is,can the OEM front fender be modified to clear?
I would also see if that will not clear,how about a 1.85x18 fr. rim w/ a 3.50x18 front tire ?
I just like the look of the stock front fender. 

[Jspooner]

I had those size rims and front tire on my RD when I owned one. It fits but its tight.