Tri-Y headers

bkozlow · #1 (**permalink**) 04-13-2006, 07:30 AM

If one were building a set of tri-Y headers for a Coupe what would the cylinder pairings be, using the 1985 EFI firing order compared to the old 302-289 firing order.

Bkozlow

bkozlow · #2 (**permalink**) 04-18-2006, 05:32 PM

I am really surprised no one has commented. Just for the record the old firing order for small blocks was 1-5-4-2-6-3-7-8. Original Tri-Y headsers paired the cylinders in the following order, 1-2, 3-4, 5-7, and 6-8. The question was, if I am using a EFI roller cam, EFI here means it has the newer firing order of 1-3-7-2-6-5-4-8, then what are the cylinder pairings for the headers?

Bill K

Bart Carter · #3 (**permalink**) 04-29-2006, 01:07 PM

Strangely enough, the pairings stay the same.

Woodz428 · #4 (**permalink**) 04-29-2006, 08:33 PM

I'm glad I'm not the only one to come to that conclusion. I did a quick check before heading to Knoxville earlier in the week and didn't post because I wanted to check it again, it seemed to obvious when I did it. The main thing to remember is they changed it to change the main bearing loading, so it shouldn't have had any effect.