SC headers
 

Wondering if anyone out there has experience or opinions to share on tuging size for headers for a stock SC, you know 1 1/2 v 1 5/8 v 1 3/4? (and yes I did a search)

Mark,
What's the very most important word in your post? :p

tubing! I hate it when my typing gets that bad. Oh, well....

(what's on your mind, Peter?)

SSI's.

Noah, from the PP site 1 1/2 for up to mild 2.7, 1 5/8 for under 3.0 and 1 3/4 for 3.0 and up. Does this sound right? I'm asking as I've heard many opinions including going to 1 3/4 only on modified engines and I have an opportunity for a good price on 1 1/2 headers. (not really worried about heating the car)

The same ID tubing was used from the early cars up to the 2.7's, and SSI's also use the same tubing for all the engines up to 3.0. If you're building a high-compression, hot cammed, 46mm carbureted 3.0 that will mostly see high-RPM track duty, then you'll gain some top end power from larger ID headers.

But with all things related to engines, there are tradeoffs. Smaller ID intake and exhaust will give you better mid-range power at the expense of the top end; and vice versa. Basic fluid dynamics. When it comes to exhausts, bigger doesn't mean better. The exhaust should match the engine, and a large ID exhaust on an otherwise stock (or mostly stock) 3.0 is going to reduce power, not make it.

Then ... there is the discussion of "stepped" headers and collectors and 3 to 1 and out or 3 to 2 to 1 and out ...

Buy the SSIs used ... they are equal length sort of headers with heat. :)

Work well, bolt on, ~15 HP.

.....and last forever. Mine are now 20 years old and look almost as good as the day I bolted them on (except for a few old oil burn off residue areas, but that's normal for an oil leaker). :D