pontiac 400 6X heads. any good?

[azkkn]

i pulled the heade and intake from a car i just bought, and i scrapped the rest of the car, it had 6x heads on it. are they worth any thing? are they good for anything? let me know

[Rob]

From what I remember, those are late 70's heads on the 400. Not really that good from what I heard. That might have changed since that was quite some time ago.

[Squat13]

It all depends...... the 6x heads are great with a littel porting but the yeild a low Compression ratio(i.e. 9:1). There is a Low compression 6X head is the one you want... YOu can tell its a small chamber 6x by a 4 stamped in to the side of the head between the #1 and 3 cylinder exhust ports. These heads were used on the HO 400's and the standard 350 pontiacs and will give you more power due to the fact that there compression chambers are MUCH smaller.

Most Pontiac nuts just go with the edelbrock casts, which you will make more power with, but the cost is around 1100$.

The link below is to an extensive pontiac head chart. Just remember that all 455 heads have compression chambers that are too big for your 400.
Pontiac head ID chart

[Squat13]

Also a littel note....... Stay away from 4x heads..... you will only get about 8.6:1 comp ratio

[birdman83]

6x heads

I have 6x heads on my 75TA 400bb they are ok heads but they aren't worth anything

[Joe 1320]

It's been a few years.... but if i remember correct, the castings are thinner than the older heads and warp/crack easier when the headgasket goes. In a performance application, there are better choices but they aren't too bad in a stock type cruiser.

[Squat13]

Have you ever seen the wenzler heads for the old Pontiacs...

Here is a link to to some different heads flow numbers.

Flow numbers

Note that the ported 6x has some close numbers to the Wenzler stock head

pictures of the wenzler heads

[N20LT4Bird]

I have 6x heads on my 75TA 400bb they are ok heads but they aren't worth anything

Yea, not worth too much as they are very common, but guys do use them in an application where a lower compression ratio is needed (ie. forced induction). As noted above, they can be ported to flow decently....

Why did you toss the car? Didnt you just buy it on ebay for 180 bucks or seomething? I dont think you will get enough out of those heads to make it worth your time.....if you pulled the motor, than maybe....

[Squat13]

Give you $180 for the complete motor and trans!

**EDIT**

Didnt see you were in maine
Nevermind

[markd79ta]

Actually, the 6x 400s totalled about 7.6:1 compression and put out a whopping 170-80ish HP. The 6x-4 W72 400s totalled about 8.3:1ish compression and put out about 220hp. The 6x head can flow fairly well, but are pretty much throw aways...I believe the combustion chamber is over 100cc. The whole motor, if intact, can be sold for about $250-$300 as a core. If you were going to build the motor, you would want a different set. Even with the 6x-4s on my T/A, I still plan to change them out and wrap them up as the originals. I have the #16 heads on the Firebird 400...R/A III heads...It should be right around 11:1 compression.

[Squat13]

Actually, the 6x 400s totalled about 7.6:1 compression and put out a whopping 170-80ish HP. The 6x-4 W72 400s totalled about 8.3:1ish compression and put out about 220hp. The 6x head can flow fairly well, but are pretty much throw aways...I believe the combustion chamber is over 100cc. The whole motor, if intact, can be sold for about $250-$300 as a core. If you were going to build the motor, you would want a different set. Even with the 6x-4s on my T/A, I still plan to change them out and wrap them up as the originals. I have the #16 heads on the Firebird 400...R/A III heads...It should be right around 11:1 compression.

Well you know, a nice mill job and some dome pistions and your in business........did I mention how much a large shot of Laughing Gas likes that 9:1 Comp ration. I just think that even though the heads are cheap, large, and Iron, they are still a good head.

About those RAIII heads.... how much do you think a set would go for.... $500, $600 if yo can even find a set thats not being sold on a motor. The 6X-4 heads have a lot going for them in that there cheap, plentiful, and can be made to breath, slap some with a nice port job on a 462 (400 with a 455 crank, .030 over) and you got a nice combo.