I have a very similar rebuild on my 71 lark front end with a 350. In addition, I have Moog 5385 spring and 1 inch sway bar/bushing upgrade in back. My car handles very well in cornering and at speed but still sense some flex and twitchiness that are probably inherent in a 50 year old design. I also have a Z06 corvette so its tuff to compare handling but I'm happy with my Buick setup. The springs overall added about 5/8 inch height increase over stock and did "soften" a bit after wear in. BTW, I have A/C on my car so there may be a bit more weight over front wheels/tires. I also have a fairly fresh set of BFG's on the car which help to keep it planted. Hope this helps!
I think it has more to do with steering/road feel. Toe is very important as well as not enough can cause the car to wander. The box I have in my car is a quick ratio and my steering does not have that over assisted feel.
My 68 GS400 feels "light" in the front also compared to the modern cars I drive, its completely stock and I think its just the different feel of the cars from then to now. Its funny because I had that same "light" feeling thought the last time I drove the '68. The whole feel and driving experience is different. I typically drive a 2017 Sliverado or the 2007 Solstice which almost sits on the ground
What you're feeling might be bump steer exacerbated by your upgrades. Global West has a redesigned steering arm set you can bolt on in place of the stock ones. Small change but makes a big difference in feel and control: https://www.globalwest.net/a-body-1...2-steering-knuckle-arms-repair-bumpsteer.html
What tire pressure are you running? After some advice on the forum I upped mine from 36 to 42 psi and it transformed the way the car drives. Still has some old car 'looseness' but there is way less wander. The Electra does have granny friendly power steering and if you wanted to - though I would not recommend it - you can go lock to lock with one finger at a dead stop! This does reduce the amount of feedback through the wheel but I've got used to it. Bob
How tall does the car sit? What size are the bfg’s How is the camber? You can put a tall top ball joint in the car and help keep camber neutral as opposed to going negative like our cars tend to go. Help keep front tires planted.
I'd want to see alignment specs before weighing in. Some shops will set up a zero-toe alignment just because "old car" but I don't like that. -Bob C.
It's difficult to say, but if you don't have a bunch of experience behind the wheel of one of these, it might be normal? These cars do have a lot of ride and not much road feel...
Actually, it's just the opposite, the camber on the outside tire goes positive. That is why our cars understeer. The taller ball joints can reverse that, camber goes negative on compression, much like more modern cars. It dramatically improves handling.
You did not indicate speed when saying that the car feels like it's floating. New springs, sway bars etc don't solve this problem if you were not specifically paying attention. If you watch old movies with these cars you'll notice at highway speed the nose of the cars are pointed up in the air when stock. The front end literally is being lifted. Record video of you car at speed to better understand what is going on. Drop the nose down 1/2" at a time till the car handles to your liking.
Oh yeah they get bad negative camber on lift. It looks funny to watch but handling is sacrificed tremendously. He mentioned springs raised car 5/8” so that didn’t help at all. Like you say needs to get nose down. And the tall upper ball joints are great for camber thru out the suspension travel.
Front wheel well arch is 26 inches above road surface; BFG tires are typical 245/60 15's; camber was set to stock spec at last alignment/nothing special as I remember. Hope this helps.
I just measured my Buick 1970 Gs 350 with a 455. I’m 25.5 inches from top of wheel opening to ground. 215/75r 15 front tires . I use ac DELCO springs 45h0045 which are not currently available it appears. It’s hard to say without seeing but good points made here. Toe is so important as mentioned where tires pointed and send our cars and is caster and camber. Caster directs you straight positive degreed and neutral camber keeps you planted. Car seems a little high. Is rear lower or higher?