FYI, go to www.performancepeddler.com and put in the code EBAYROCKS at checkout. The price for the 2.5" kitwill drop to $359 or so IIRC. I don't know if that deal is still going but it was when I got mine not long ago. Oh yeah, stick to the 2.5" because it is more than large enough and much cheaper.

[edit] Just checked the site and it was $349.28 with free delivery.

 

For normally aspirated motors, 2.25" works very well in the 300 CID (5.0 L) range, and 2.5" is similarly well suited for NA motors of about 350 CID.

On the street, 2.5" is something of an overkill for a NA 289, as is 3" for a NA 350-ish motor.

Norm

 

Thanks gothand, I was looking for an exaust. You solved my problem for really cheap and a good exaust too.

 

You people and your HUGE exhaust. I would think 2.5 is even pushing it in this case.

 

Here are a couple of links to different sites regarding exhaust info. Good luck!

http://www.magnaflow.com/wideopen/performdata.asp
http://www.nsxprime.com/FAQ/Miscella...austtheory.htm

 

For a 289, I agree, but he is looking ahead to a 347 . . .

FWIW, an engineer that I know of from another forum and who has done a fair amount of dyno-tuning for some small-bore road racers (little old British sports coupes, not Hondas) has consistently ended up in the 2" to 2.25" range (single exhaust) for engines of only about 90 CID for either best torque or best power (not necessarily with the same arrangement, however). But think in terms of 2.25" pipes on a V8 engine that makes nearly 400 bhp from about a hundred fewer cubic inches than you have in a 289/302. That's big. And it works.

Norm