Kooks makes different size headers. I have h/c, intake & tb. Why wouldn't it be better to get the 1 7/8" or even the 1 7/8" stepped to 2" instead of the 1 3/4" ? Would the larger sizes make less power on my car?

 

larger diameter primaries are generally used for larger cube motors, or motors spraying a large shot of nitrous(both require the dispelling of large amounts of exhaust quickly). stock cube motors breath just fine w/1 3/4. you may gain w/1 7/8, since you have good heads and a good intake. you'll probably gain some top end hp with the possiblity of losing a little low end tq.

 

Anyone else know?

 

You might look at this:
https://ls1tech.com/forums/showthrea...ighlight=kooks

and from what I have read on this I agree with cyphur_traq, and you'd probably be fine with 1 7/8 but I don't think i would get 1 7/8 stepped, IMO.

 

Ok...its not like I didn't spend over 6 months researching headers my damn self. Don't take my word for it

 

When you get in to 2" primaries you dealing with an all out race header. Big CI or hella compression, hella built engine, that needs all the header it can get. In my opinion a 4 or 500hp engine doesnt need any bigger than an 1-3/4 stepped to 1-7/8 or just a 1-7/8.