Big block or small block springs?

I am building a '70 GS from the ground up. It was originally a 350 car. I am replacing all the springs. My question is, All the kits are for an A body. A big block Chevelle engine is far heavier that a Buick big block. (I have heard a 455 with an aluminum intake weighs about the same as a small block chevy.)
I am installing a 455, iron heads, aluminum intake,with a/c. Which springs should I use? o No:

 

Steve - I would stick with the 350 springs.

 

Get the 455 springs - Moog 5450 or 5536.

 

I would say 350 springs.

 

If Moog makes a replacement spring specifically for the 455 then I'd probably go with that. If they just list a-body big and small block then I'd go with the small block.

On my '66 Skylark, like you, I swapped in an iron headed 455 w/alum intake and I used Hotchkis 1" lowering springs spec'ed for a small block chevelle and it sits just right. I don't have the AC in yet but I'll be running a much lighter aftermarket system so I should be OK.

 

i'm planning on a 350 to 455 swap and i am sticking with the new 350 springs i put in a couple years ago due to helping weight transfer at the strip :3gears:

 

Just out of curiosity, what is the weight difference between a 455 and a 350?

 

less than 100 pounds

 

the big block ls6 454 springs would be way too much for your buick & they are difficult to install.

 

Thanks for your help guys. I am going with th Hotchkis Sb spring kit. It will lower the car 1" also. :Brow:

 

I had the same dilemma this summer (350 swap to 455), I went with the BB kit from hotchkis, talked with one of their suspension experts and he was the one who directed me to still go with the heavier spring.
Not sure if you can tell the diff? o No:

 

Personally I wish I still had my 350 springs. My car launches like crap, seems to really accentuate the bumbs, and I think one of the reasons is the MOOG big block springs. I wish I had a taller spring with more travel for a better launch, I think these would ride nicer too.

-Bob Cunningham