If your gonna lower it with SS springs you might still need to cut a coil off of them. The 4.1 is lighter than the lt1... You could go with I b body shock to get the stiffer valving you probably want...
I'll let my son know, at least those springs are easier and cheaper to come by, than intrax or srints.
Shocks are another story, I recomended Bilstiens cause' that's what I have, but Monroes sensa-something has been recomended also.
It'll be his decision to make, we'll see what happens, keep you posted.
sens-tracs are ment for a stock suspension caddy. Put them on my 89 Brougham, and they came on my Grey Buick. Too mushy for me. The 89 bounced high and low(due to the soft springs), while the Grey Buick more so floated. Now my 94 Fleetwood with Severe Service's... now thats a much better ride. It did have the stiffer suspension code(FE2), vs a normal fleetwood. Very nice ride. All it needed was a lil stiffer springs up front, as the air lifts in the rear stiffened it enough for me, while removing that silly reverse rake.
Personally, I've never had a car with too much suspension travel given speed bumps, potholes, rough pavement on high speed corners, etc. You have to have enough spring to keep the car off the bumpstops at all times. Bottom it out, and you're no longer in control. With less travel, this takes a really, really stiff spring.
All this only applies if you want to be able to freely drive the car hard. Put it on the bumpstops if you're just going to idle around.