Inliners International Forums General Discussion Hi Performance 250 Header

I have a Chevy 250, it should be a late 60's block.(can't find anyplace with that casting number listed) I was wanting to put a set of headers on it, but was wondering if I had to do any mods to the engine in order to do that. PAW lists a set of Hedman Hedders part# 69310 that should work. It says that they come with collectors, gaskets, and bolts. BTW, my motor has the split intake and exhaust manifolds. Thanks for any help.

There may be a little clearance issues between the header and intake, but a file or grinder usually is an easy fix. Another issue may be a difference between the header flange and intake manifold thickness. You may need to modify the clamps etc to get the intake/exhaust gasket tight against both pieces.

How are the manifolds held on? Is it only by those clamps? If so, why would the headers come with bolts? If there is a difference between the thickness of the two, how would I modify the clamps? Sorry for all the questions, but I'm doing an engine swap and would like to install headers while I'm at it. Thanks in advance.

The bolts are probably for the collectors. As for the clamps, if they won't fit as is, then cut, grind, weld, etc... to make them fit, or make some from scratch out of barstock, etc...

Welcome to the world of hot rodding! Gearhead is correct where may need to modify the existing clamps to make them thinner to fit or grind down one side of the clamp to compensate for the different thicknesses etc. You can also use washers, channel or whatever to get good even clamping on both intake and exhaust. Langdon has some nice aluminum clamps, but you may even need to modify them.

So if the header thickness is smaller, then I will need to grind off some material on the intake side of the clamp, right? How would you use washers? Sorry for all of the questions, I'm just used to my 327. Thanks in advance.

Do NOT use washers. Any kind! Not for a street driven daily driver. Go with the original type intake/exhaust clamps or have a welding shop custom cut some pieces of steel or irona and grind them to fit with your grinder. Be sure to use case hardened or grade 8 Bolts to secure everything down.

I pulled a set of clamps off an old 235 block and they work perfectly on my Offy single 4 barrel intake and Dynomax tube headers.

The headers came with their own bolts and washers but they were too short to use with the OEM clamps. I used a couple of the on the ends to secure the exhaust. But for the shared mounts I used clamps and a combination of hardened bolts I had lying around that would fit.

I experimented with several things before deciding that washers and short bolts just won't do. I bought stainless exhaust header bolts from Alloyboltz. Didn't work. Here's what I found when I used washers and short bolts.

A. They allow header movement, even when torque beyond recommendation.
B. They never fully sealed the exhaust headers to the head.
C. Non-case hardened washers will certainly bend over time and cause leakage.
D. Case hardened washers will still allow the flange to slip and move underneath, no matter how tight you torqued it.

Washers didn't work for me.

big, is it a six-into-one header or two-three's? I have my PAW Catalog in front of me but it does not specify. I am looking for a six-into-one for my 250 '74 Chevelle.
Ken

p.s. Dynomax lists #85023 header(s) for 250 Chevy.
Ken

It's two 3-into-1 headers. 2003 PAW catalog, page 1058. 11th listing down. Part #69310. I got them a few days ago, they look nice. Nice, thick flanges. I ended up ordering mine from Summit, the price was $8 cheaper and they arrived on the 3rd night.(along with my Pertronix kit) PAW has some good prices, but from my experience they take ALOT longer to arrive. Not bashing, just informing. BTW the headers I got were long tube.

Ken, have you got an electronic distributor? If so, what did you set your base timing at? Also, have you changed your intake manifolds? Thanks in advance.

big, I still have the original points distributor and stock coil. I have the base timing at about 8 degrees. I also have the original stock intake manifold and carb along with stock exhaust. I have two coil-in-cap HEI units but they won't work because there isn't enough room for them because of the A/C compressor which is located just above the distributor. Here is something I know but have not heard anyone mention. On my '77 Chevelle 250 factory HEI winter rat it is not a one piece cap-in-coil distributor. It is two pieces. The cap is still on the large size but the coil which is small and square shaped is mounted on
the engine and is connected by wire just like the points type system. I also have one of these set ups I saved from a '76 Camaro 250. In the coming months, as the weather improves, I am going to see if I can get this slightly smaller distributor head to fit. If it does, I can buy an aftermarket coil and I will then be faced with the same issues you are right now. But I have the feeling it won't fit and then I will order a Pertronix unit. I'm glad this whole issue came up because I will need the info from your other post to make sure I do not fry my ignition. A local guy tells me he can make a set of six-into-one headers for me and then I can have them 'aluminum' ceramic coated inside and out. We also have a '67 Chevelle Malibu Coupe 327/275 hp w factory air. I took the original Quadrajet off and went with one of the new Holley Street Avenger with ELECTRIC CHOKE four-barrel carbs. That electric choke is the greatest! She runs like a bear. Just bolt it on and go. I also bought a set of Hedman Hedders and had the local guy 'aluminum' ceramic coat them in and out. Fantastic and worth every cent. So far they have not discolored at all and they sure LOOK GREAT. Anyway, back to the 250, I want to do some experimenting - carbs, intakes, cams, exhaust and a few other ideas I want to try. Tom Langdon told me to use a carb from a Ford Pinto but did not go into detail. I'm not sure what carb this is. I have also heard that an inline six will run better and get better gas mileage with a two barrel carb. I go junkin' a lot and just maybe I'll try to pick up a fuel injection system with computer from a late model V-6 Camaro. Could be interesting. At any rate I want an electric choke on my carb.
I do a lot of bracket racing. My next project is a 250 or 235 into a '62 Corvette. That will be a whole different story.
Ken

Ken, go with Pertronix. I just swapped in my 250 today. I had the Pertronix unit in there, but couldn't figure out what to do with the resistor wire. So I put the points in and tried to fire the motor, and she wouldn't. I finally got ahold of a Pertronix tech, and they said it was fine to splice the + wire into the resistor wire. So I put the unit in again and hooked it up. The motor fired up the first try.

With the open headers on there, the 250 sounds like a big block on steroids. I've got to do some fine tuning with the timing and carb (2 barrel), but overall it's been cool.

Only took me 2 1/2 to 3 days to swap them out. Not bad for a 17 year old, in the front yard, on plywood.

BTW, Hedman's headers were bolt on. They work great. No grinding required.

Thanks for all the help everyone.

[This message has been edited by bigchevy66 (edited 04-02-2003).]

big, congratulations on your swap and getting her fired and running. It is still cold here in NY but I was out looking at my project today and I'm 99% sure I will have to stay with the stock distributor. I saw one of your other posts and I too will go with the Accel Superstock Coil. Two questions: Does the Pertronix conversion use the stock distributor cap? and What are you using for plug wires? 7 mm 8 mm ? Not bad for a 50 year old.
Ken

Ken, yes the Pertronix unit will fit under the stock cap. All you have to do is remove 2 screws, pull the points & plate, and put in the new one with the new screws. You have to run the new wires too, but it's easy as pie. I pulled my Accel 8.8mm wires off my 327 and used them on the 250. They're kinda long, but the work.

BTW, is there a "correct" way to install the rear oil pan seal? My 250 is leaking like crazy.

Thanks for the help.

Are you sure that it is the oil pan And Not the rear main seal? I fit is the oil pan always add a little RTV where the gaskets meet. Hope this helps }[oooooo]




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NovaMan/Twisted6/Larry

hello...another trick to no leaks is use RTV on front and back of oil pan and gaskets , BUT DO NOT TIGHTEN FULLY FOR 24 Hrs.... this way the RTV can set up and create seal...fully tightening immediately can cause a premature leak ,if not immediately,due to RTV squeezing out.....after 24 hrs snug bolts up tight......have fun....

Lee

[This message has been edited by LeeLites (edited 04-05-2003).]

When I had the pan off I looked at the rear MAIN seal, and it was fine. The rear oil pan seal was mangled up pretty bad, so I installed a new one. But, I think i over tightened the pan and squeezed the seal out.

Is there any way to install a new rear oil pan seal without pulling the pan?

Thanks for the help.

will that header fit a stock intake? what kinda chevy do you have bigchevy66

83fbody- I have a '66 & a '68 Chevy C-10 1/2 ton. The 250 came out of the '66 and went into the '68. The 250 has split intake and exhaust with the STOCK 1-barrel intake. Those headers fit perfect. The only problem I had was I had to remove the clutch bar that bolts into the block in order to install them. After I installed them I bolted the clutch bar back on, and all was well.(as far as the headers go) Just make sure to get ALL of the bolts started before tightening down.

BTW, I now own a 1988 Honda Civic Hatchback with a 1.5L INLINE 4. It's a Honda, but it gets great gas mileage. Does anyone know where I can look up some of the specs on that car?

Thanks.

check out this site, click on specs
http://www.civic4g.com/

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250L6/TH400 daily driver '66


[This message has been edited by 83fbody (edited 04-09-2003).]

Where's the best place for split headers? I'm looking at them for my '78 Nova.

Novaboy009-I would check PAW, Summit, and Hedman. I got mine from Summit, but they were made by Hedman. I'll look in some of my catalogs for you. What are the specs on the car/motor?

83fbody-Thanks for the site, I'll have to check it out. I've gotten bitten by the import bug, and have to rice-out the Civic now. The car gets great gas milage. I went 300 miles one one tank, and put in $11 ($1.389 a gallon) to fill it up. Much better than my '68 C-10.

Thanks.

big, You said your transplanted plug wires are a bit long. One of the best investments I ever made was $30 for a top-of-the-line spark plug wire tool. Cut the wires to length then crimp. You can put a little oil on the wire to get the metal pieces to slip on easier if necessary. It crimps the ends just like a factory crimp and with a little practice you'll be a pro. The best part is the price of the parts - I think the metal ends are fifteen cents each at NAPA! We junked a Chevelle with a 305 but we had recently installed a set of MSW 7mm Magnetic Surpression Wires. It was a set from Pep Boys that were made for the 305 and 350 but most of them were longer than necessary. I saved them especially since my son had paid about $27 for them and they were less than a year old when we junked the 305. We went through his 327 this winter and he wanted new plug wires. I took the wires I had saved, cut them to exact length, crimped them at both ends and put them on the 327 while he was not home. I even had enough left over for the coil wire. It took a couple of hours and the parts cost about three dollars. He was surprised when he saw them and asked, "Where did you get those wires?, they're perfect and I love 'em." I told him I had "made them" from his 305 wires and invested less than three dollars. The best part - when someone looks at his motor he tells them "Check out my plug wires, my Dad made them for me."
One thing about car guys, they are easy to buy for on their Birthdays and Christmas. I've gotten quite a few of my tools on these days and it makes it easier on some people who don't know what to get you!
Ken

Ken- I've seen those tools before, but haven't gotten one yet. That's a great alternative to buying new wires. I have Accel 8.8mm wires right now, but I really like the MSD 8.5mm. I'll just use what I've got though.

In reply to the second part of your post: That's what it's all about. I'm 17 and think and talk about cars and trucks all day. My friends don't get it, but it's something the whole family can enjoy together. Car guys are easy to shop for. Just get them a new tool or 2 and they'll be happy.
BTW: I saw American Graffiti this weekend for the first time. Great movie, with some cools cars.

Thanks for all the help.

as a 16 year old garage rat, i totally know where you're coming from. i have a '68 C20 with a 250, that, well, needs quite a bit of work, but its ok. i have lotsa time. i was looking into heaaders, but then i got the hair brained idea to just make my own. i have the plans drawn out, just need to follow thru with it. i think it'll work. right now i'm working on the bed/box panel. then i need to repair the cab mounts, and corners, and yeah. its a task. then, on to the intake, hopefully atleast a 2 barrel, maybe a 2x1 or a 2x2, still undecided. well, i kno where you're coming from, good to see pple my age into straights. gotta love 'em. everyone preaching 350's...yeah.

thanx for your time.
SamWise

as a 16 year old garage rat, i totally know where you're coming from. i have a '68 C20 with a 250, that, well, needs quite a bit of work, but its ok. i have lotsa time. i was looking into heaaders, but then i got the hair brained idea to just make my own. i have the plans drawn out, just need to follow thru with it. i think it'll work. right now i'm working on the bed/box panel. then i need to repair the cab mounts, and corners, and yeah. its a task. then, on to the intake, hopefully atleast a 2 barrel, maybe a 2x1 or a 2x2, still undecided. well, i kno where you're coming from, good to see pple my age into straights. gotta love 'em. everyone preaching 350's...yeah.

thanx for your time.
SamWise

250 Header ? I have long tube headers w/2-3s . Will power steering brks. clear header tube on #1 cyl. Just installed ps last wk and love it. Very easy to instll w/ REZ kit

Holy back from the dead, Batman.

SamWise, I'm thinking about making my own headers too. I'm planning to eventually go with a turbo, so I may just use a stock exhaust manifold unless I get too radical with it. I'm eventually going to strip my '68 down to the frame and redo everything. I just need the time and money. Then I can work on my '66 after that, and strip it down.

Chopper66, I really don't know. I don't have power steering on my truck. Or power anything for that matter. If you look in a catalog for the headders it should tell you if it'll work with PS or not. Good luck. John

Chopper66, I have a 292 in my '65. I used a set of Dynamax ceramic coated headers listed for a Chev Pickup on it. Great for ground clearance, no problem with crossmember or clutch cross-shaft. I have an Offenhauser intake on it with the mid '70s style power steering. Seems to me I had to do a touch of grinding on the backside of the top bracket but nothing serious. It's in the paint shop right now so I can't tell you how it all works but heres hoping.....

GMDAD Thanks for the info. I did email the company, there Tech Support & recived info to day .Thanks Again I will post results when finished.