I am planning on going with a 455 in my car at some point ,if you have 350 springs in the front (no A/C)now and your 455 has aluminum heads and intake will the springs still need to be changed ?

 

In my opinion, no.
There is not a huge weight difference between a small block vs big block Olds engine. The heads & intake should make it close enough that you don't need to change springs.
Of course, it's no harder to change springs after the engine swap if you decide you don't like the way it sits or rides.

 

I agree, leave the springs alone for now and see what it looks like after the swap. With the aluminum heads and probably manifold, headers, you will be lightening the load of the BBO considerably. I bet it will be a wash on the weight.

 

Thanks guys ,thats kinda my thoughts ,I've always wanted a 455 in my Olds and if I'm going to rebuild an engine I MAW go BIG !!

 

MAW, lol!!!!

 

With aluminum heads and intake you'll most likely find that the springs are still too stiff. My 350 car sat just right with a stock built 455...when I got the aluminum EVERYTHING the car rose 2" and looks like a gasser. I'm trying to fund a spring swap using QA1 coilovers.

 

My 72 originally had a 350 and still has stock springs not much of a difference once the 455 was in. maybe an inch lower. Easy swap just have to have matching motor mounts and brackets. I've heard hood clearance can be a problem, but I didn't have any and my hoods not original though.

 

Ha ha MAW has cost me a lot of money over the years! It seems strange that the 455 with aluminum components would be that much lighter than a 350, but I guess it's possible. My 455 with an aluminum intake and no AC now resides where a 3.8 with AC used to, and it sits just about the same, but the spring rate is too low and the springs are too long, so there's a lot of float. You may want to plan on changing the springs just to take out the float and give you more control with the extra power. The ideal time to do this would probably be after you get the new motor in, and you can see how it sits and how much the front end weighs.

As for engine height, the 455 is about an inch taller, all other things being equal. Depending on which intake and spacers you have now and use with the 455, this could affect height also.

 

From some of the info I gathered online it looks like the 350 weighs in around 560 lbs and the 455 weighs 605 ,not a lot of difference really and with aluminum heads saving approx
50 lbs that places the BB right there with the weight of a SB with iron heads .

 

A bare block is 400 pounds with iron heads and all accessories on its about 700+ pounds

 

I'm not positive but the info I have is just for the motors no accessories ,but wouldn't the accessories add the same amount of weight for both motors?http://www.carnut.com/specs/engdim.html

 

That should be correct. We weighed mine no exhaust or starter. Every bracket and pulley was on.(no fan) Have a steel balancer on and the distributor was even on. It came in at 712 or 715. It was 71 something can't remember exactly. And that's with no AC pump or bracket.

 

An aluminum part of the same size and thickness as an iron part will weigh about 1/3 as much. Iron heads weigh 47 lb more or less, and BBO intakes about 56 lb. SBO intakes are probably about 45 lb. I guess. That difference is about the Olds advertised difference between SBO and BBO engines.

 

So if you had an aluminum intake and headers
and aluminum heads you could be close to
the small block weight so that SBO springs wouldn't
be that affected .

 

That seems to be the general consensus! If you still want it higher, you can always do the springs later.

 

Not even close. I have personally weighed a bare 455 block using the finest Chinesium bathroom scale that WalMart sells, and it came in right at 200 lbs. FYI, a WMW 403 block clocked 170 lbs on the same scale.

 

I Was told a bare block weighed 400. We used an old chain scale older then the car itself. the complete full motor came in at 710. It weighed myself and it was accurate but I only weigh 130. So I can see if the accuracy diminished adding more weight. Bit I thought it was pretty accurate.

 

Was that the bathroom scale the wife uses?? LOL!

 

Sounds about right to me.

I can lift a bare block on an engine stand halfway off the ground (2 wheels on the ground, 2 wheels off) to "hop" it up or down a step-off without a problem, and I'm no Hulk, so that lift being = to a bit over 100# (including engine stand portion) sounds accurate.
I can also "roll" a bare block around on the floor without much strain - if it were 400#, then no way, dude.

- Eric

 

If a bare block weighs 400 lbs then I must be superman. I can lift a bare, BARE! block by myself and put it in the bed of a truck. I would imagine that Joe's scale was close...200 lbs sounds and feels about right. When you add the crank, rods, pistons, cam, heads, and intake...I would think you'll be in the area of 500-600 lbs.

If you take the difference of aluminum heads and intake into account you can imagine that the weight savings are quite substantial. I can carry one cast iron "E" head with both hands. Conversely, I can carry both aluminum heads (one in each hand) by the center exhaust ports.

I think a 455 with a completely aluminum top end is still substantially lighter than a 350 with all cast iron components.

 

So we've taken 10 days to determine that a 455 with an aluminum top end is about the same weight as a 350, interesting.

 

You know...I have one of each sitting on the garage floor...I guess I could weigh each of them and then get the weight of the aluminum heads and intake to compare, but why would I wanna end this conversation with an absolute answer? I like that nobody knows for sure lol!

But, I would make it 11 days and say that a 455 w/ aluminum top end weighs LESS than a stock 350.

 

I would have to say that I really don't care........LOL.

 

What's really interesting is we've talked about this for 11 days, thanks to an unamed source, and not even an argument! Go figure!

 

I am putting coil overs in mine. I don't have a clue as to what any of the the parts I am changing are going to do to the ride height. It's just money right? Just don't tell the wife.