i dont know if there even useable. they have been sitting in a buddys garage and the springs are all rusted and hes not even sure what they came off of.

but the only numbers i can find on them are1256 and 4241.

does anybody know what these are. i could really use some help?

 

From a 2001 - 2004 LS1 as for the rusted springs, I would have them worked over before using!

 

so would that be 241 heads or what?

 

Yes 241

 

okay thanks.
now i have another question. how well would these heads work over stock heads on my 99 5.3.
the 5.3 i about to be getting a tr220 headers and stall.

 

They would do alright, I would have them milled to bump compression. What heads are on your 5.3?

 

You likely have 862 or 706 heads on your 5.3 now. I'd stick with them or find some 243/ 799 heads because 241s won't be worth your effort.

 

yes i would get them milled if they are even any good. and truthfully im not sure what heads are on my 5.3. all i know is they are just the stock heads that came on it.

 

I would find out what heads I had first before spending money and like blue says, I would go for a set of 706 or 243s. You could pick up a good set cheaper than paying for the machine work it will take to get them cleaned up. Get new heads and mill those for compression and wall ah

 

You'll be able to find your casting number on the side of the head towards the front of motor