[76WS4]

I got a '76 455 lined up to buy for my TA and would like recommendations for the best all around iron cylinder head to use for it running 93 gas. I'm looking for the best bang for the buck. Aftermarket aluminum heads are out for now. Thanks for any in put ,Joseph.

[b-man]

6X-4

[Blackened]

I was wondering the same question. You may want to consider the following info:
http://www.hotrodders.com/forum/pont...ds-235457.html

[ponyakr]

You'll get a lot of posts on this one. But most of the guys are still asleep. I agree that the 6x heads are probably the best choice. One reason is that they are so plentiful. They came on 350's and 400's for the last several years they were produced. And since they came on all the "junk" 557 blocks, guys don't mind selling the heads seperately.

But there are other heads that are almost as good for your application, such as certain 4x heads, 5c, 96 and I'm sure others will chime in with all the other numbers. Avoid the heads without all six exhaust manifold bolt holes. And be sure to start with a head that has screw-in rocker arm studs. You don't want any head that will give you more than 9.5 compression, for pump gas. I'd go with a little less, just to be on the safe side.

For street use, the 455 has plenty of torque to melt the tires without a lot of compression. So my advice is "a little bit less is better". And I have had lots of street and bracket racing 455's. That's my 2 cents worth. I'm sure others will have more.

[74 SD455 Formula]

1971 Cast #96. Used on 400 4barrel carb cars.Like a Firebird,G.P.,GTO. They are known as the R/A III of 71.

[1971WARBIRD]

Hi Performance Pontiac did a test years ago, and for the street, big 2.11 intakes and smaller 1.66 exhaust worked well.
cheapest and easiest to find will be the 6X. i like the #8 myself, then cut to 9-1 compression. #4's will put you close to 9.5-1, which is good if you are good at tuning the combo. 2.11 and 1.66 valves.
4X small chamber are good also. you have to look closer as some are small valve(1.96 not the bigger 2.11) intakes, and some of the earlier heads have press in, not screw in studs. 2.11 and 1.66 valves.
7K3's are big valve, screw in studs but don't have all 6 holes for exhaust manifolds, so you have to buy and addaptor to make them work. 2.11 and 1.77 valves.
1971 96 D-port heads, have all the best stuff; big valves 2.11-1.77, screw in studs and make reasonable compression 9/9.5-1, but will be the most expensive to buy, and more than likely over kill.

[ta man]

I agree with the 6x's either the 4's or the 8's easiest to find.

[PONTIAC LARRY]

6X -4 from a same year '76 350 looks correct on car and makes a MONSTER torque / HP improvement when coupled with true dual exhaust, 160 T -stat and good tuning... but if you find a good deal on #96 , 7K3, 6X-8 , 5C-8 4X-8 etc I wouldnt hesitate if its a good deal ready to run and maybe ported already.. If the '76 455 still still has the slightly lower compression stock style pistons style pistons I would stay focused on the 89-93 cc heads like the 6X -4 though. The others are more like 98-101 cc

[MescaBug]

+1 on 6X-4, 7K3 and 96.

7K3 are my favorites. Big valves, good 'stock' flow numbers, CC perfect for 455. You have to deal with the end holes for the exhaust manifolds though.

[se428bandit]

6x and 1975 5c (4 stamping) will also work and are the same as 6x.

[76WS4]

Looks as though the 350 6X heads would be the best choice for my application unless a pair of those 96 heads comes along. I appreciate all the responses. You guys are great.

[takid455]

I have 72 7M5 heads, exhaust and intake manifolds if interested. All port matched. Bolt on and go. Removed for a set of aluminum heads.

[BAD2000TA]

As mentioned, the #96 heads have all the best stuff. That's what I used when I built my 455. Still affordable compared to aftermarket heads.

[b-man]

The 6X and 5C heads have one advantage over all the other choices, that being a superior intake port shape with a better short-turn radius. They are a better candidate for porting if you decide to do that later on.

They are also available in 2 chamber sizes, 92cc for the -4 (I've seen them with as much as 98ccs) and 101cc for the -8 (sometimes up to 105ccs).

These 6X and 5C castings can be had for about half what a #96 head goes for.

[FrankieT/A]

I vote 6X-4's

[Ben M.]

Originally Posted by b-man

These 6X and 5C castings can be had for about half what a #96 head goes for.

Yup. Even better is that the 5C & 4X heads are thought to be "garbage" by so many people you can often get them for next to nothing - 6X heads have a reputation by people and thus tend to command a higher price.

[Skip Fix]

"The 6X and 5C heads have one advantage over all the other choices, that being a superior intake port shape with a better short-turn radius. They are a better candidate for porting if you decide to do that later on.

They are also available in 2 chamber sizes, 92cc for the -4 (I've seen them with as much as 98ccs) and 101cc for the -8 (sometimes up to 105ccs)."

Agreed! The port is a better shape as well as the exhaust port. My original 78 -8s were 97.5cc, some -4s I picked up were 93cc. The -4 I smoothed the ridges and shaved them 0.050 and they are still 93. I have a set of -8s with the ridges off that measures 105.5cc now.

[PunchT37]

Sleeper look on a `76? 6X#4`s, especially with the champhered `76 piston.

[PONTIAC LARRY]

Originally Posted by PunchT37

Sleeper look on a `76? 6X#4`s, especially with the champhered `76 piston.

exactly to my point. Its what I would do with a 76 black ext gold honeycomb 50th annivery ta 455 4 speed if i had a time machine to go get one new after placing some choice bets to pay for it

[4mula73]

Mpmsmuscle and I have a set of 6X-8s that he ported per Jim Hand's book. They could be milled to get your CR target. If you're interested, please PM me.