Hi Mark:
I don't know anything about the topic but I've been told that tubes that are too large can have a detrimental effect on exhaust efficiency. I'd suggest you talk to my friend Tom Dawson at Dawson Racing Headers for an answer to your question. I had Tom custom-make the 180s for my car for about the same $$ as a pre-made set. He also did some beauties for Dennis Daley's street Pantera. Tom's number is (951) 928-0969 and his web address is http://www.dawsonracingheaders.com. His shop is in Nuevo, CA.
Who cares about the debatable performance increase from 180s? They're sooooo beautiful....
Matt Merritt
#2171
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