Big Block Weight Differences

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d55dave

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Good morning all! I am just building an aluminum headed low deck to replace my old iron headed 440.

Old engine was a 440 with iron heads, new engine is a low deck 451 with aluminum heads.

Anyone have a rough idea on what the weight difference might be between the two?

Thanks!

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I think 70-80 pounds is about right.
You're 451 will weigh about 7 pounds less than an iron headed small block, isn't that cool !
By the way, did you find a camshaft?
 
I doubt it will be as much as 70lb, more like 40-50. BBM heads are not as heavy as some BB heads, so there is less weight saving.
 
I doubt it will be as much as 70lb, more like 40-50. BBM heads are not as heavy as some BB heads, so there is less weight saving.
Crankshaft is lighter, pistons are lighter, rods are lighter intake manifold is lighter it adds up, it's about 35-40 pounds less in heads, it's 25-30 pounds lighter from rb to b block, stroker stuff is easily 5-10 pounds lighter,
 
I doubt it will be as much as 70lb, more like 40-50. BBM heads are not as heavy as some BB heads, so there is less weight saving.
cast iron big block head is about 60#'s each vs aluminum head about 30#'s each.
There's 60#'s savings right there. the 440 block is several pounds heavier as well is the crank.
 
It sounds like he weighed his options before deciding on the Aluminum heads. Let's not make light of his decision.
 
I am pretty sure the BB factory iron heads [ bare ] weigh 44-45 lb. Valves, springs do not enter the equation because they are needed with any head. Now, I could be wrong about the weight but I am 95%+ sure. Valves with alum heads might be lighter if they have 11/32" stems.
 
I am pretty sure the BB factory iron heads [ bare ] weigh 44-45 lb. Valves, springs do not enter the equation because they are needed with any head. Now, I could be wrong about the weight but I am 95%+ sure. Valves with alum heads might be lighter if they have 11/32" stems.
Aluminum heads loaded weigh 29 pounds factory big blocks loaded are 50 pounds
 
Thanks for all the answers everyone. What I am figuring now is just shy of a 100 pound weight savings. Some funny and clever answers were provided!
 
I don't remember where I saw it.... but what I saw was that the b-block was not much lighter than an rb block.
Crank and rods can be lighter, the 400 forged pistons I had were very heavy.
So, I would assume the majority of the savings will be in the heads and intake.
My guess would be around 60-80 lbs, leaning to the lesser end of that.
(Aluminum rat heads save that over the iron versions in the heads alone)
 
I don't remember where I saw it.... but what I saw was that the b-block was not much lighter than an rb block.
Crank and rods can be lighter, the 400 forged pistons I had were very heavy.
So, I would assume the majority of the savings will be in the heads and intake.
My guess would be around 60-80 lbs, leaning to the lesser end of that.
(Aluminum rat heads save that over the iron versions in the heads alone)
I hate bbc iron heads... damn it, so heavy
 
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