Okay so im doing a head swap on a ls1. Putting on stock 241 heads I believe i need the 3.910 gasket bore size but I ordered the wrong one which is 4.125 bore size was planning on doing it this weekend but won't be able to get the right ones til Tuesday unless I overnight them. My question is can I use the 4.125 gaskets or are they too big of a bore size and what would it affect?

 

I wouldn't run them. 4.125 is quite a bit larger than the stock gasket bore.

 

It depends.

Nothing wrong with running the larger gaskets, other than the fact you'll lose some compression. Lots of people run the 4.100 bore LS9 gaskets on the 3.780 bore 4.8/5.3 engines with boost.

 

Would the compression loss be noticeable even? Other than the slight compression loss any other stuff it may affect? Thanks for the quick response guys I appreciate it