Im gonna stick with my 4.8 for a little while I believe and take my time with my engine build, but still plan to do a little here and there. Hell I may wind up being happy with what I end up getting out of it (fat chance but we'll see)

Right now the engine is completely stock. Plan to cam it in the not so distant future. While doing a little research on heads for different combinations Im thinking of building, I got to thinking about maybe doing some heads on the 4.8.

I HAD a set of 241 casting heads I sent to get milled by a friend, but never worried about getting them back. Assuming he can find them, what would be better on the 4.8? some milled 241's, or the 862s?

I looked here https://www.performancetrucks.net/fo...d.php?t=434396
and dont think the flow alone justifies the labor of swapping them, what Im thinking however is some hand porting, and shaving the 241s to get the compression back, will the larger intake valve of the 241s make the swap worthwhile?

Any info is appreciated. Thanks

 

back up would like to know some info on this .....

 

i say 241s ls1 has them on there flat top,it might do something on a 4.8 with flattops...i would do it

 

241 are junk the big 66cc chamber kills them Even if u milled them .050 you will still lose compression
my 243s are cut .040 and have a 60.5cc chamber! stock was 64.45
Take the big valves out the 241s and install them in the 862 heads cut them to actually gain compression

 

any one else with an opinion ?

 

Ported and milled they would be better than the truck castings i think, the compression loss would be minimal, i went from 243s on my 5.3 to 317s and it still runs great.

 

862's are the way to go. Although, after milling, I have some problems with 93 octane on really hot days. E85 cures it. Go figure.