Mopar Dave, couple more questions. What constitutes a "tuned" collector? I am considering a merge collector into a straight exit (non-megaphone) vs a formed straight collector. Also, do you kmow if the collector has to be straight, or is it only the length and diameter that is critical? I want to do side exhaust old school NASCAR style to help deflect some air around by rear wheel openings with the tips just behind the door openings. Trying to break a 237.3+ mph record. Thanks.