[FC] Damage w/o ZDDP & '63 car motor in '63 FC...potential problems?

[David Houston]

This spring I witnessed motor failure in my friend's '66 110 using the 'energy conserving' 10w-30. He drove many highway miles daily and his valves disintergrated. I thought it was the unleaded fuel. Until it was shown that ZDDP was no longer in the oil. I've since been getting my supply from Eastwood in PA.
My next point of inquiry is what potential problems could I expect from using an 80 hp car motor in my FC? Other than the oil tube, it looks the same, but I know the FC engine is built sturdier.  I'm adding ZDDP to my oil which stopped the foaming in the oil. I have a PG with a 3:55 axle ratio. I run on Hi-test and rebuilt both carbs. I'm afraid to go faster than 50 mph, because the motor seems to be straining but not running too hot! Any advice?
BTW I put 15" Chev Caprice rims on my front axle and they fit perfect. The suspension doesn't hit. Would a '63 FC be stable with narrow 15" radials all around (205/65-15)?
Thanks
 
1962 Greenbrier camper
1963 Greenbrier Hippy Pad