Attempt at new intake/exhaust for inline 250
 

Okay, so ... both of my exhaust manifolds were pretty rough - one was leaking horribly and rattling, the other one had a hairline crack. I took my spare intake/exhaust, split it, had the intake sandblasted, repainted it with Eastwood exhaust paint, bought new Dynomax headers for $160 from Mothertruckers, coated them with Eastwood header paint, then went to reinstall everything.

The damned headers interfere with the intake, so I can't get it in. The headers bump into:

Drivers side motor mount
Clutch linkage
The bottom sides of the intake for cylinders 1-2 and 5-6

I thought this would be straightforward, but I'm going to need to butcher the bottom side of the headers to make them fit.

Here are some pics if anyone is interested in what I got going...I will say this: The Eastwood exhaust and header paints are GREAT. Very easy to prep up and work with. Goes on smooth and one can would have been enough to coat my headers 4x.

Headers, before paint:

http://shifty.org/uploads/header01.jpg


After paint (1 coat):

http://shifty.org/uploads/header02.jpg


Intake after separation, sandblasting and paint:

http://shifty.org/uploads/header03.jpg
http://shifty.org/uploads/header04.jpg


This is the front header mocked up (notice the engine mount and clutch linkage - it bangs right there a little bit):

http://shifty.org/uploads/header05.jpg
http://shifty.org/uploads/header06.jpg


Here are the places where it's not meeting up. I'm going to need to massage both places, but I don't know what I'm going to do about the clutch linkage, because it's not going anywhere. I thought these headers were supposed to "fit" without these problems, but I was sorely mistaken :D

http://shifty.org/uploads/header05-2.jpg
http://shifty.org/uploads/header06-2.jpg

man =/ I did clifford headers on my 292 and from what I understood they had no problem putting them on. took about 6 hours I belive with the full exhaust done to. those do look like they are abit odd fitting.

I wish I could help you with what my headers are on mine, but I don't know the brand, they were on the truck when I got them. I THINK they are Clifford headers, my intake is a Clifford. My setup is like yours though, with a 3 spd stick and they fit fine. I had some header leaking issues and wound up going with a Clifford header gasket, all problems solved. I've also heard nothing but good things about Mothertruckers, so I'd be willing to bet they will surely make things right by you.

Aww, seriously, this isnt' Mothertruckers fault! I'm totally happy with the product, just ... in my case, I'm having a helluva time trying to make everything fit. :\

Shifty, I got around a clutch -push -rod -hitting -the -headers problem ['71 Jimmy K/5] on a 350 w/Heddmans by "joggling" the lower ear on the Z-Bar so the front end of the clutch push rod missed the header tube. You could also shorten the push rod -- just make sure your clutch action is good and you don't need anymore room on it before you do.
The Clifford headers I have on my 292 were fitted on back in '78. I don't recall any major hassles. Just some ball pein dimples to clear the angles of the 4V Offy intake (very similar to stock configuration). Also Clifford sells the same p/n headers for both the 250 and 292. With the 292 heavy duty tall deck (+1.75") the downtubes clear the motor mount and Z-Bar pivots easy. Maybe the geometry is not as good with a 250? Your Pacesetters look a lot like the Cliffords. After a 25-year run on my last 292, I recycled mine by getting the headers hot-tanked and bead blasted, then painted them w/ 1500* VHT Nu-Cast Iron and they're doing great on my fresh 292 build.
Hang in there man, these L6s take time because there are fewer experts still alive who remember the old tricks. Results will be worth it.

something you may consider that i did on the 71 k20 with headers, cut the bar off the bottem of the z-bar and move it over about 3 inches to the left.. never had a problem out of mine

Thanks, guys. I am going to shorten the rod by about an inch. I really need to do something about the bar itself though.

Here's one for you: My Z-bar (what I guess is the Z-bar) and the Y-shaped mount that holds it to the motor are both shot. The cloth rings and round rubber seals on both of them are totally shot. I really need to tear it down, clean it up and rebuild it.

Where do you find replacements for these rings and what are they called? Does it come in a kit or something?

I put an O-ring in mine to replace the rag type seal. I think it was 11/16" I.D. X 3/32 diameter O-ring. It's been a while since I did this but from what I remember it worked well, don't forget to use the zert fitting to grease the sucker.

I also have a rubber ring around the ball on the end of the Y-shaped fork that connects to the engine block. Basically, the ball that slips into the Z-bar is notched all the way around the circumference and there was a cracked up, rotten rubber seal of some sort seated in it. I can post pics if needed.

I got my stuff from LMC. I disassembled a junkyard Z-Bar [keeping the original intact for reference], blew out the old grease, stripped it with a wire wheel, repainted it and reassembled it with new parts. Even added a new grease fitting. P/Ns: felt washer 30-0695, spring (lock) 30-3103 (x2), seat 30-2392 (x4).
The L6 engine ball stud and bracket assembly could be refurbished, I think. If the bracket is still good, but the L6 ballstud is worn, you could drive out the crimped-in old ballstud, and drill and tap for the threaded [ but still-available] V8 engine ball stud, maybe tack welding it to the bracket or backing up the threaded part with another nut. If the "Y" bracket itself is shot, it could be duplicated out of 1/4" strap steel and the V8 ballstud (engine) p/n 32-6124, affixed in the above manner. I believe the GM dealers still stock this part OEM. I compared a surplus SBC engine ballstud unit off my Jimmy to the L6 set-up and it was the same length and diameter, except for a threaded extension that screws into a V8 block. So if you can't find an L6 engine ballstud and ["Y"] bracket assembly in a junk yard, it could be fabricated by someone who has a lot of time and some talent.

From the first pic, it almost looks bent. IIRC, it should be perpendicular to the frame. It seems like it's pushed forward on the end opposite the frame. Maybe years of stabbing the clutch hard? Or... maybe the pic is deceiving.

Mine has this thing in the pic attached to the clutch z-bar thing and to the engine. Sorry I don't have a better pic but I think you can see it.


Mike

I use those headers with an Offy intake...had to grind on the bottom of the intake and dent one header pipe...and that was with an AT.
Next time I would go with short cast headers, less hassle, better fit, less leaking.

Gotta make a decision tonight: grind the headers, grind the bottom of the intake ... or grind them both :D

I'm on a mission to get the truck running tonight. Hopefully I can reinstall the Z-bar with the Y-bar and headers already installed....guess we'll hafta see :\

PS: 68OrangeSunshine: Thanks for the part numbers!

Shifty, I would'nt grind the headers -- not much metal there -- can't you ding them with a big ball pein hammer?

Well, I don't have much of a lip to grind off the intake, so I'm guessing I need to take off about 1/8" from this part here to make the intake/exhaust ports marry up right:

http://www.shifty.org/uploads/header05-2.jpg

Yep, I'm guessing that's why it's leaning forward in the original pic. Nothing to hold it back on that side. shifty, do you have this piece installed... just not when you posted the pics? If not, this may be why you're banging the header tube with the clutch.

XXL: There was never anything mounted in that hole. The only thing mounted to the block was in the two holes above that (see the bolts there - it's where the Y-bracket mounts up)

What is supposed to go in that single hole?

My guess is passenger car clutch linkage mounting. Nova applications are supposed to be different. I don't really know. My experience is strictly with Chevy light trucks.

hey, 68OrangeSunshine,
You list the following parts:


Felt washer 30-0695
Spring (lock) 30-3103 (x2)
Seat 30-2392 (x4)

Questions...
1) Are these the LMC part numbers?
2) What are the seat and spring for?
3) Don't you need two cloth washers?

I think the Y-bar takes a cloth washer just below the ballstud end. Pretty sure the Z-bar takes one on the side closest to the frame.

My mistake. It looked like that's where the bracket should go to mate with the Z-bar. I see that the 2 holes above is where it actually mounts.

Gee, this is like an autoshop quiz... Lessee,
1] Yes. Sorry I don't have the GM p/n. Sometimes if you have the right number, the parts guy at the dealer can pull up some gems.
2] The 'seats' are bevelled nylon rings. The interior of the Z-Bar is chamfered to seat one then the ball of the ballstud, then another nylon ring to trap the round ballstud, then it is locked in place by the 'spring'.
3] Yes. You're right, You need one at each end. I didn't order a second one because it isn't illustrated in the LMC catalog. When I installed the clutch linkages, I used a red felt battery terminal anti-corrosion washer to hold the grease in the Z-Bar at the engine bracket side.
OBTW, don't forget the 'spacer' p/n 30-2906. It's a special lockwasher for the specific application, it holds the threaded end of the frame ballstud in the clutch bracket on the frame. Bending down the ears onto the sides of the nut -- once it's in place -- keeps the nut from walking. 'Clip-linkages' 30-1602 are real handy to have. Get extras and keep 2 in the glove box. Also after 34-odd years of operating, my 'linkage-swivel' 32-6010 was almost sawn thru. This is one part you should try to get from a dealer, if they still have 'em. The GM one is superior to an import repop.
Have fun.

interesting I-6 pics
 

Hey Shifty I thought you might be interested in these pics and this guys project.



http://www.chevyasylum.com/64c10/64c10_11.html

Thanks, V²! Was cool to actually see someone doing the same thin. Glad to know this is not a rare occurence.