[Z28_302]

Looking for a good set of headers for my 69 Z28 - have the stock manifolds/heads on it now but would like to get more torque. I've lowered the front end 2", so I'm worried about clearance with long-tubes. So - for more torque and decent ground clearance, what should I run?

[Gary L]

Thorley Tri-Ys.

[Z28_302]

Anyone like/dislike Doug's or Hedman?

[69Z28-RS]

Headers generally add 'high rpm horsepower', not low rpm torque. if you do install headers, and 'torque' is an issue for you, then you should keep the primary tubes on the small side (1-5/8" and no larger than 1-3/4" dia). PS> torque is generally not a strong point with the 302 (or any big bore, short stroke engine). long stroke engines (under square) generally delivers higher torque and lower high rpm power; Oversquare engines like the 302 deliver high rpm horsepower at the expense of low rpm torque. The Tri-Y design is as good as you will get for 'torque'...

[Gary L]

Unless you are talking about an over-square 406.......

[TMessick]

Thorley 376Y1 are 1+5/8" primary tri-y and fit great. Good clearance to PS box, collectors tuck up really tight and should help your midrange a bit. They ain't cheap though...

Doug's D368 is another popular choice that seems to fit well, but the 1+3/4" primaries aren't likely to help your midrange torque much.

Doug's D308 is a 1+5/8" full length, but I don't remember hearing much about these as to how they fit, etc.

I'm running the 376Y1's on my 69 with the "other" 5.0L (307) and I'm happy with them.

[Gary L]

With the help of another TC member I modified my back drive linkage to work with my Thorley's.

[69Z28-RS]

Originally Posted by Gary L

Unless you are talking about an over-square 406.......

*G*.. That's too much mass and too many cubes... *G*.. a 'big' 368 or so is about as large as I'd go to keep the 'high winding' nature....

[Gary L]

I wasn't talking about a hi-winder.

[69Z28-RS]

Yep.. 406 is a stroker.. perfect for a truck.. for hauling..

[x77-69z28]

I have hooker 1 5/8 tubes on mine. They tuck up pretty nice, have never bottomed them out. Did you change your heads as well?

[Gary L]

Originally Posted by 69Z28-RS

Yep.. 406 is a stroker.. perfect for a truck.. for hauling..

No, a 406 is a bored, stock SB 400 from Chevrolet.

How did you select 368 CI? Explain that to the 377 CI crowd.

[Zman]

Here's a set of Doug's, 1 5/8, nice fit and finish, plug access and clearance is good, very happy with them.

[USN1969SS]

I am interested in the tri-y's also and have been searching quite a bit here but haven't found anything on spark plug clearance until Zman here. For a 350, are all plugs clearing the tubes...no need for short plug or heat shield on wire?

Dave

[Zman]

FYI, I used Accel shorties to get proper clearance.