Jump to content

Header hunt

Recommended Posts

  • Replies 11
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images



http://i138.photobucket.com/albums/q251/datzenmike/L%20Z%20Heads%20and%20Motors/enginepossibleL18620exhaust.jpg[/img]"]enginepossibleL18620exhaust.jpgEarly L16 or L18 (bottom) exhaust manifold. Factory knew what they were doing. Hard to improve on that. They are: (like a low maintenance g/f)



Never wear out.

Good as a header for almost all applications.


Easy to install.

They FIT!!!!!!!!!

They don't come loose, leak or require maintenance. "fit 'em and forgit 'em"


Header's are:



Rust out unless you get the expensive ones, but they still:

Are loud and annoying (give it a couple of weeks, you'll see)

PITA to install, plus cutting up your exhaust system.

Often don't fit or need to be modified to clear obstructions.



... spend time wondering where the extra 10 hp is that it was supposed to make. You spend time re-tightening bolts every two weeks. You watch it get rusty. No one knows you have one because they can't see it while driving around. Eventually it dawns on you that you paid $ for the pleasure of spending a week end installing it, cut up your good exhaust down pipe, removed the motor mount to get the friggin' thing in, twice actually as you had to dent the pipe to clear the torsion bar, the droning noise makes your $2K sound system useless and you would put the old manifold back on if it wasn't so much work and if you hadn't thrown the manifold away.



See: http://forum.ratsun.net/showthread.php?t=13093

Edited by datzenmike
Link to comment

i agree with Datzenmike. I have a nissan comp header and for my Long rod motor it rubs the floor pan a bit as it is meant for a L16/L18 motor in a 510. I even heard from dave rebello who built my motor that even the stock manifolds are very good and told me if I change out to just get a stock manifold. he says he did not see any major change in hp and actually for lower rpm's the stock is better. If I get another man I will change out as I would like to get rid of the knocking at times. I know of other guys who have stock mans of hot motor setups with good results. I would say if you can jet hot coat it if you want cooler performance.

Link to comment

there is a little more to this.

Since you have a truck you have torsion bars and you need the correct Y pipe fore this to route correctly.



maybe a 76 has a good manifold already but im not a 620 expert


Top End performance has short ube manifolds as these will clear or is really short to where a exhaust shop can route a pipe to clear the torsion bar.

However these headers are painted cheaply with black paint which will rust. You need to get them ceramic coated which will cost another 100+ $.


The header flange can be a little wavy so maybe needs to be machined also or see if they leak once installed. I seen a few peopl erun these with good results. others say they can leak depending on gasket. But most I have seen are OK. heres a fofot of mine but I dont have it installed. its for looks


Edited by banzai510(hainz)
Link to comment

L18 through '74. L20Bs from '75-'77 used U-67 square port exhaust with intake and exhaust manifolds bolted together. If you want to use the L16/18 exhaust then you will need another intake too. '78 and on used W-58 round port exhaust head and manifolds that were seperate. Square port exhaust will work on round port head though.


If I had a '75-'77 L20B I would skip all the bother and expence and just leave it, seeing as there is no gain to this. Stock works fine, many do this for the 'clean look'. Maybe have a custome 2" exhaust system and a turbo muffler put on instead.

Link to comment
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.