These aren't close to being new, but would I see much difference in power and ride (suspension) if I switched from a 1990 safari L 377(fan) to a 1991 formula mx 470(liquid). And are the old formula mx's reliable at all, because my safari seems to be holding itself together quite well. Thanks for any comments.

The 470 will have alot more power and they are pretty reliable too.
Had a 88 version of that motor and drove it very hard. Never let me
down even after 5500 miles on it.
The sled will handle better but as far as ride..... they both suck!IMO
These year sleds tend to blow out shocks easy in the front(and the rear).
When new they're ok but buy now I'm sure that sleds shocks are starting
to sag. Sled will sit real low to the ground. My buddy has a 91 Mach and he
put new shocks in the front and a sc-10III in the rear!!! Not bad! Pretty nice
now but everthing around it is getting tired. Both trailing arms rusted up
and broke. The original skid was rusted tight so I hope your is in better
shape. Keep it lubed up!!!