Beretta.net

is there a differece between 3100 and 3.1 heads , i mean will 3100 heads bolt on a 3.1 block , and if so is there any performace gains to doing it

They will bolt up, but you'll need to use the complete 3100 sfi top end and then measure for correct pushrod lengths.  You will need to make other corrections to get certain things to "hook up" and work properly.  If you are thinking of doing this, I'd use the big port 3100 or the 3400 top end. ÂÂÂ

However, it would be ideal to just swap in a complete 3400 or 3500 engine. ÂÂÂ

Try running a search, there should be a few threads on this very same thing.  In the end they mostly all end with swapping to the complete 3x00 engine or not doing anything at all. ÂÂÂ

thanks , but see i race berettas at a local dirt track and when we lift the hood in tech and the end of the night we can have a motor bigger the 3.1 so basicly we have to have a 3.1 plenum on there , im just tryin to sneak a few more ponys with out getting busted

Then no.