I heard that some headers actually reduce HP and I do not want to make that mistake. I have a 302, holley 600, pulling a 4 speed. The cam is modified. What header is likely to create the best bang for the buck.
I agree with madspeed, long tubes are generally the best. Shorties usually have some kind of drawback in the power department. They are an improvement over stock manifolds, but you have a trade-off between power and ease of installation/clearances. I found a bunch of information regarding shorties when I was researching them to put in our old 84 convertible. You might have some luck researching shorty headers vs long tubes for Fox bodies and get a rough idea of the trade-offs.....
Appreciate the feedback.
Aren't long headers difficult to fit and mess with ground clearance?
Interested in why stay with 1 5/8" . Was planning on it but only as a matter of fitting existing. help me understand this.
Also, is there a way to commute HP without a dyno? close I suspect.
Yes, long tubes will more than likely be more challenging than shorties to install. As for ground clearance, I have long tubes in my II and it doesn't seem to affect it much and it's lowered a little in the front. I'll let someone more knowledgeable in the ways of exhaust explain in more detail about the 1-5/8" primary benefits, but I do know that too large of an exhaust can actually hurt performance. Here is a link to an old Hot Rod magazine article concerning 2-1/2" vs 3" exhaust. While not exactly the answer you're looking for, this may help to explain the reasoning.
I have about the same motor as you in my 66. I went with Sanderson shorties and love them. Do they cost me a few HP? Since I don't race and run it flat out for long times, I'll never know, but some things I found looking around the Sanderson site http://www.sandersonheaders.com/lets-get-technical.html
I have about the same motor as you in my 66. I went with Sanderson shorties and love them. Do they cost me a few HP? Since I don't race and run it flat out for long times, I'll never know, but some things I found looking around the Sanderson site http://www.sandersonheaders.com/lets-get-technical.html[/QUOTE