Almond900

Sold the small block, got the big block, found the 4bbl carb and intake, just wondering if I should do the bb springs too? The guy I got carb and intake from also has a-body bb springs I can get, how much difference is there between the bb and sb springs? He says he has front and rear bb springs, what is the difference in the rear?

joe_padavano

There's no such thing as "big block rear springs", since engine weight has no effect on the back of the car. Cars with the FE2 suspension did get different rear springs, however. As for the front springs, the difference between a BBO and SBO is about 50 lbs. Changing the intake from iron to aluminum just about makes up the difference. I've done the BBO swap without changing front springs, but I think the 68-72 cars sit too high in the front anyway. Have someone sit on the front fender and look at the difference in ride height.

Almond900

That's what I kinda wondered, as it sat with a small block it was about 1" high in front, everyone I talked to around here kept saying they handle so much better but I was worried about it sitting even higher with the bb springs, I was able to find a cast iron 70 4bbl carb and intake so I won't be shaving any weight there

Fun71

It really depends upon which springs you get. Some are listed as small block with AC / big block without AC. Just depends upon the spring ratings.

Check this post for the specs I found for Moog front springs as well as a couple pics of my car with front springs that are listed for both SBO and BBO:

https://classicoldsmobile.com/forums...-68-442-a.html

Almond900

Thanks for all the charts guys, this is what I found for springs, fronts are moog 5382 and rear is moog 5385. I guess I am just wondering what to expect for a ride height with these springs. 72 cutlass s 455 all iron no a/c and auto trans. I can buy fronts and rears both new in box for $40 for all, I just don't know what to expect for height from them

oldcutlass

When you swap engines the front will probably drop 1.5 inches. For $40 I'd get the springs. Here is a cross reference to all Moog springs:
http://www.moog-suspension-parts.com...il_springs.asp

Almond900

How do I figure out the dimensions of my stock spring to compare the new spring to?

OldsPerformance

I didn't change springs on a few big block converted cars and again like Joe said with the savings on the aluminum intake I beleive the diffenece is a mute point. Good luck

Durf

I would drop the motor in and see how it sits with the 350 setup, if you don't like it put the BB springs in. Joe and Olds performance are speaking from experience. My experience was lightening up my 455. Aluminum Heads/Intake, lost the air conditioner. Man she sat really high in the front. The car came with FE2 suspension, replaced with springs for 350 WO air. It still sat high I then cut 1 1/2 coil off the new springs. Like the look much better now.

rad

I put a 455 in a nova once, and it sat it right on the headers pretty much, it had a 250 six banger originally, so i put 350 with ac springs in and it actually rode a little high in the front even with a stock intake and iron heads, if it were me id put it in and see where yer at.