My 69 SS427 came with F40 suspension. The L72 big block did not have A/C, so the springs are shorter but firmer with heavy duty front sway bar and no rear sway bar. This combination held the front of the car up. The rear springs are heavier too, more coils and size. You could not beat the way My car handled with heavy duty shocks, factory blue ones, that they said were computer generated. The F41 suspension was generated for tow duty. I just put a rear sway bar on My car. The sway bar kept the tires on the ground when cornering while towing. The tires would come off the ground without the sway bar because the panhard bar would let them lift, but plant the inside tire on the ground. It was harder to slide the rear. Also wide tires would hit the fenders. Did You notice how the wheel drops when they the car is jacked up. A sway bar prevents this. F41 suspension rides a little softer. I am installing KYB heavy duty shocks. I used to use heavy duty Cadillac air shocks to raise the rear and give tire clearance. Factory cars came with 6 inch rims with G70 tires. They wore out the centers. I used 7 inch or wider with H 60 tires. I disagree with Jim, F40 with heavier rear springs or air shocks will handle better. I had My car since 1968, with many miles driven. NICK L72