Hello, I'm replacing my exhaust manifolds, risers and elbow tube. My question is will the elbow tube that fits a 4.3 liter engine fit my 5.7 liter engine. I've found some that say they are for a 4.3 liter but not 5.7. They seem to be the same dimension as what I have, just wondering if they will work on my engine. They say for use with a 3" spacer which is what I have. Thanks for your help.