Aluminum Block vs Iron Block

[lotussutol]

I have been searching this site, google, and youtube looking for information on doing an LS swap into a 1980 Datsun S130 280zx.
I am trying to find out if the headache/extra money of making sure to find an aluminum block LS is worth it.I have not been able to find much out.

What I have found from searching and my questions under the statement (correct me if I am wrong in my research).

After the swap weight is shifted to the back.
An Iron LS block weighs approx 100lb more than an aluminum block LS.
With an iron block LS swap the weight balance of the car is 40/60.
With an aluminum block LS swap the weight balance is closer to 50/50.

Questions
Will the avg driver notice the difference in an iron block vs aluminum block?
If I go with an iron block should I get stiffer rear springs for the added weight mo

Has anybody done an L83/4l60e swap into the ZX? I am wanting to do an L83/4l60e, AC, no power steering swap into my 1980 Datsun 280zx. But, if the aluminum block gain isn't that big and iron block doesn't make a notable difference I will open up my engine options.

If any of this is out of line/off topic. I apologize.

 

Thank

[calZ]

When you're saying 40/60, are you meaning 40 rear and 60 front? Generally front to rear weight bias is referred to as F/R. 

 

Removing 100lbs from an engine on a car the size of an S130, all else being equal, is going to shift the weight 3-4%, not 10%. I think an average driver is going to have a very hard time noticing that difference. 

[lotussutol]

I was reading. I will find the quote that a person weighed front/rear total before after swap and that the rear weighed more post swap due to the LS sitting further back. I can't say if it  is true or not though. and I agree. I don't think 100 lbs the avg driver is not going to notice.

 

[NewZed]

Here's some Z numbers, for aluminum.  The transmission comes in to play also.  

 

 

http://www.brokenkitty.com/zcar/zcar.htm

 

 

 

[G-Tech]

I had a small block chevy in my 280zx and it was very nose heavy...the car lost alot of handling....when I switched to the LS (which was alot more work, believe it or not) the car got all its balance back. Its lighter now then it was from the factory....well worth beeing alum block if you ask me

[JMortensen]

FWIW, I have an aluminum 5.3/T56 in my early 240. Pre swap was 49.5F / 50.5R with me in it, after swap is same weight within 2 lbs, but 52/48 with driver weight, so more front heavy. This is with the engine 1.5" from the firewall, but also has a heavy plywood splitter, heavy aftermarket PS rack gigantic wheels and tires, etc. With iron block should be closer to 54/46ish. You can make that handle if that's what you're after, just takes some working with alignments, etc.