Well I've spent the last few hours reading through archives on here and classicalpontiac and have seen many opinions. Figure as long as I'm sitting here avoiding actual work I might as well get some more.
It's time for the exhaust system and I'm wondering what size tubes to use 2.25 or 2.5"? It'll be dual exhaust. Just about every posting I've read through is a discussion of 2.5 vs 3" but I haven't heard many people say anything about 2.25. In reading on here I found that Bjorn ended up with 2.5 and I think Vikki has 2.25. Most postings I've read recommend 2.5 but I'm not sure that I need it. I believe the 400HO and Ram Air IV used 2.25" so I'm thinking that would likely be fine for me as well.
Here's my situation. 67 coupe with a 400 bored 0.060" and a summit 2801 cam. Stock 1.5 rockers, #62 heads with no porting. TH400 with whatever torque converter was on there when I bought the car; all I know is it's pretty large and I'd be suprised if anything much bigger would fit in there. Not sure what rear gears I have but can check once I get home if need be. I have the headers that were on the car when I bought them but I don't know much about them other than they're the 3 tube design. I'm not planning on doing any racing or sustained high engine speed running; this thing will be a weekend driver (once it actually moves...). Of course I'll push it a bit but I'm not gonna be going to the strip. Or at least that's what I say now.
I'm just kinda looking around and have seen a few systems on summit's website. I can add in an H or X crossover later if need be. They have a 2.25" and several 2.5" systems. I'd like to order a system and put it on there rather than having a shop do it just because I like doing things myself, but I have no means of doing much more than fit and weld.
so anyone have an opinion? Maybe 2.5 won't hurt so I might as well go with it? Maybe 2.25 would give better low end which is probably where I'd do most of my running anyhow? Maybe I wouldn't notice the difference so I should quit wasting your time and just rock-paper-scissors myself for it?
