I dropped the 400 block off today to get rebuilt and was presented with questions that I have absolutely no knowledge about. So, I figired I would post them here

What headers are good for these motors? There is more on the market than I could ever sift through.

Will the headers and exhaust that are on the 350 that is in the car work with the 400?

I am currently using a 750 cfm carb, will that work?

Upgrade manifold or use the stock one?

Thanks in advance.

We'll need to know more about what you're building to answer better.
Stock or performance rebuild?
Which heads?
Are you having them ported?
Which CAM?
What size exhaust are you running?
You might want to consider long branch manifolds. They were made for our cars and less hassle than headers (IMO).
I'm sure others will chime in with more questions.

Can't use the chevy exhaust manifolds.
750 cfm carb is good.
Use stock pontiac intake manifold.

For the most part, headers are okay if power increase is what you're after. The suggestion to use "long branch" manifolds is "solid". With some port work, they will out-perform "cheap" headers.

If you're determined to use headers, DO NOT buy them based on "ease of installation". Seldom are the "good" headers "easy". 1st gen 'birds aren't too bad, though, at least compared to other brands (like Camaro...). Headers are installed for power, not for "easy".

For a more serious approach to performance, high quality 4-tube headers can't be "beat". For "out of the box" fit and finish, Hooker is the best, "hands down". They're a bit bulky so sometimes, there's ground clearance issues. Mad Dog is another brand becoming more popular. We have several customers using them and zero complaints. They "fit" and have good tubing length and consistency. They offer a bit more ground clearance, as well. Doug's is another popular brand that DOES make power.

Which ever direction you decide to go, manifolds or headers, buy them "bare" (uncoated) and send them to a coating shop. The ceramic coating applied by header companies is "short-lived". We've seen them rust out in less than 2 years. We send them to Thermal Tech in Hopewell, Virginia, to have a "thermal barrier" applied. Thermal Tech is also a Doug's dealer. They offer an "iron colored" coating for the manifolds, too. Jet Hot and Swain are two other companies that come to mind. This will protect your "investment" better than any other method.

Jim

Thanks for the responses. I'm sorry that I don't know more. The builder will call tomorrow and we will discuss all the specifics. I figured that I would jump the gun and ask you guys first. Thanks for all the responses. I will post more when I know more.

Thanks again.

I had Jet hot coat my Hedmans over 10 years ago and they still look good. They are the long tube and have some ground clearance issues. If I ever explore exhuast options again, it would be the long branch manifolds or a good set of coated shortys.

Definitely keep the stock manifold and if you have a Q-jet, keep it, if not try to find one.

I have a set of Doug's Headers on my car. The install is really easy as long as you reverse the instructions and install the passenger side 1st due to the need to clear the oil dipstick tube. You definitely need to hoist the motor up to get the passenger side in.

Since you are rebuilding your motor, just install the motor without the headers and install them right after you get the motor back into position while you still have the engine hoist available.

Ground clearance is outstanding as they do not hang lower that the subframe rails.

I just put some Hooker Competion (cheapest Hookers) on my Bird. I compared them to Hedmans of a similar price point and the Hookers fit better (not easier but better) i.e. they tucked up under the car better and cleared the steering linkage and oil filter better. The Hookers also seemed to be better made, heavier flange, etc.

Good observations. Hooker "Comps" are smaller than SuperComps, true enough. If the 1 5/8" tube is "big" enough for your application, they're probably the best bet. And Tom is right. Hookers ARE very well made.

The long branch manifolds are infinitely preferable to "shorties" Shorties are for "bragging rights", not power production. Factory cars in later years use them because they're both cheaper and make more power than the cheesy Chevy exhaust manifolds.

For those not familiar, you might want to talk to Mark at Mad Dog. They're relatively "new" to the industry, but LIKE Pontiacs.

Jim

I have the original exhaust manifolds, if that makes any difference.

LBMs, stock intake, stock carb. Being a purist, this will always be my advise, "always use stock parts". For MANY MANY reasons, one being less BS in every way! IMO of course...

Definately something to be said for using factory parts. Pontiac engineers knew how to make reliable power in these cars. With few exceptions, most of the performance parts I've installed on my car were not the simple bolt on as advertised.

What application did your roller camshaft and lifters come stock on?

Hedman 35270's on my 69 project fit excellent and hang even with the subframe. I have Blackjack's on my 67 that fit excellent as well, but hang down further than the Hedmans. Both cars have power steering. The ownly place both needed a little "dent" was to get a little more space between a frame mount bolt (motor mount) and tube #1.

Thanks again for all the responses. I should hear from the builder sometime today.

Ok. I have some good news and some bad news.

Bad news: the heads are 15's.

Good news: well..... you guys are going to have to give that to me.

Bob,

What's bad about 15s? The chamber volume is quite desirable for a 406 intended for 93 octane. Mill them .020" and you have 86! You must "CC" them, of course, but I just did a pair this week, and they measured 90.

15s have small valves, too. This makes them GREAT candidates for porting and making good power. By using modern "profiles" on the valve seats when they're "opened" to 2.11/1.77, significant flow and efficiency is realized over factory "large valve" heads. Some mild porting and you can have a really good pair of performance heads.

There are two potential "downfalls". They have pressed-in rocker studs. They should be reomved and the holes "HeliCoiled" to 7/16-14. The existing hole is exactly "right" for the HeliCoil, and those threads are stronger than those that would be tapped directly into the iron. The other issue is the outboard exhaust manifold holes aren't drilled and tapped. Unlike the later 7K3s etc., the "boss" IS there, so it's trivial for a machinist to properly drill and tap them for your headers.

So, good news or bad?

Jim

I gathered a little bit of good news from that.

Ok, the build is going along fine and the builder is asking for some parts. We are putting the motor pretty much back to stock. We are putting a mild cam in it, nothing too drastic. But I need some guidance with a few things. We are trying the keep the appearance pretty close to stock.

I've been looking in the Jegs and Summit catalogs for headers, but there is way too many to choose from. Any specific suggestions?

Which distributors will fit the motor?

Stupid question, but are aluminum valve covers better than steel?

Thanks in advance.

Two outta three of these questions have been extensively discussed just recently.

1) Long Branch reproductions;

2) Any Pontiac V-8 distributor from 1955 to 1979;

3a) Aluminum will transfer heat from the oil to the engine compartment faster than steel. That might be a bad thing. It might be a good thing.

3B) Since the originals were steel, most choose to stick with them for the original look.

3c) Most "tall" valve covers which are often (but not always) required to clear adjustable valve train hardware are steel.

Oh, sorry ... the answer to #1 was my opinion about the solution and wasn't actually the answer to your question.

Doug's headers have the reputation of fitting the best. Hedman 4-tube headers are probably the least expensive that will fit with the fewest issues about clearance.

Hookers appear to have the most problems. (Pun intended)

For a mild build, keep the primary diameter relatively small - like 1-5/8 to 1-3/4 - if you don't go for the R.A.R.E. reproduction long branch manifolds.

Standard Hookers have issues, but if you go for a Hooker, step up to the Super Comp Hookers. They fit great, are very well built, but do hang down low on the drivers side. Most Headers will have similar ground clearance issues...

Given that the RARE manifolds are by far the best choice.

I would use the correct style chrome valve covers and would go with a stock style or HEI style Dist.

LBMs all the way. I just ordered a new set (not the long branch but the HO style) for the LeMans. I would never again have headers after owning and installing the LBMs!

On the heads, it will be cheaper in the long run to find a set of big valve heads to replace the #15's. I would suggest #62's from a big car w/ AC in thier place.


Steve

I'm with Steve on that one, particularly after seeing sets of #13's and #62's out there from between $200 (cores) to $500 (rebuilt and running).

Converting #15's to large valve, HD seats, screw-in studs, 6-bolt flanges, etc will run double that amount (with rebuild). And that's after you pay for the cores.

If you insist on converting small-valve heads, there are #5C heads which have the large intake valve, hardened seats and 6 exhaust flange holes already provided (from the factory).

There was a set on eBay last night that will probably sell for less than $200.

Just found a set of "Headers by Ed" and put them on my 67 Fb they are equal length and seem to be high quality, have yet to fire it up as I am in the middle of a total resto.