Re: 1962 Lark 40 & hustler (photos)
The 75hp has a different cylinder block incorporating different porting. It is ported for top end performance, whereas the 70 is more for better low-end and all-around (skiing, cruising, etc.). Otherwise, very similar to the 70.
Ironically, the 75 would likely be very similar to the 40 from a fuel consumption standpoint as it is a loop-charged design. I have a 1980 Johnson Stinger 75 and it gets very good mileage.
