440 head question????

[My1967GTX]

I've got a stock 1968 440 that needs heads. I can get a good deal on a set of 902 heads for a great price. My queston is what's the deal with the 902s? I've read that they have a flatter intake port and extra cooling passages. Would these be ok to run on the 68 engine or should I look for a set of stock 906 heads? Thanks.

 

[Garys1969RR]

I believe all the 68 big blocks came with the 906 head stock, no matter what car they were in. Have you checked your head casting # on your motor you have now? What is it? I am not familiar with the 902 heads, but the 452 is a good choice.

 

[My1967GTX]

I believe all the 68 big blocks came with the 906 head stock, no matter what car they were in. Have you checked your head casting # on your motor you have now? What is it? I am not familiar with the 902 heads, but the 452 is a good choice.

I know the 68 engine had 906 heads. I don't have ANY heads now and I was asking if the 1974 902 heads would be ok to run 'cause I can get them for a good price or if not I'll look for a set of 906s.

 

[lewtot184]

the '902 is a predecessor to the '452, 1975 i think. anyhow, if they're want you want then go for it. the should have an induction hardened exhaust seat.

 

[My1967GTX]

That's what I'm trying to find out, ARE THEY WHAT I WANT???????

 

[fatecaptured]

If stock is what u want, I believe all heads 906 through 452 are about the same in relation to how they stock wise. Some came with hardened exhaust seats ideal for unleaded gas, some didn't. If u want a racing head u got 2 choices. Ported iron or aluminum. One thing i found out the hard way with my 452 heads, they have a casting lip on the exhaust flange surface, so i had to grind the header flanges to make them fit. Wasn't a happy camper.
And thats all I know about that..... "Forrest Gump"

 

[My1967GTX]

If stock is what u want, I believe all heads 906 through 452 are about the same in relation to how they stock wise. Some came with hardened exhaust seats ideal for unleaded gas, some didn't. If u want a racing head u got 2 choices. Ported iron or aluminum. One thing i found out the hard way with my 452 heads, they have a casting lip on the exhaust flange surface, so i had to grind the header flanges to make them fit. Wasn't a happy camper.
And thats all I know about that..... "Forrest Gump"

Not gonna do any racing, just crusin' around,going to car meets in and out of state.Just wanted some good heads that will work for me and run good.Thanks for your help.

 

[IQ52]

That's what I'm trying to find out, ARE THEY WHAT I WANT???????

Why are you yelling? You asked if 902s will work in place of 906s. Yes 902s will work if they don't have cracked exhaust seats. You can use 250s, 906s, 902s, 346s and 452s for cruising around. If you want a little compression bump you can use 516s and 915s. Any big block passenger car head can be cleaned up and bolted on for cruising.

What is the "best" one? Everyone here will have a different favorite one. And everybody is right and everyone is wrong. Choose one and use it. You'll be right.

 

[RustyRatRod]

Go to the station wagon thread and look at the video I posted of my friend Rodney's 5300 pound Fury wagon. Stock bore and stroke 440, 10:1 blueprinted compression with 902 heads and a mild hydraulic cam. 5300 pounds with him in it and it runs 12.60s.

You won't get more experienced answer than from post #8. Be glad he's here.


Hay Jim!!!

 

[Cranky]

The 902's came on 74 model big blocks and should have induction hardened exhaust seats and you are right about a flatter port floors and usually better cooling around the spark plugs. I've never dissected any of those so I can't say for sure. How cheap are they and are they ready to run? If you have to rebuild them, I think I would look for what should be on that year engine/car just because of the casting number but other than that, they are not much difference than a 906 with exception of the seats etc. The hardened seats are the big difference. I have a set of rebuilt 902's laying here and they've been laying here for years....to the point that I would tear them down for a look see/freshen up before using them. A lot of people never heard of 902's....

 

[RustyRatRod]

I ain't even worried about hardened seats on these 516s I'm fixin to build. The car ain't gonna be 3400 pounds. It's gonna have either 4.30 or 4.56 gears. It ain't a truck haulin heavy loads, so the exhaust temp will be low. I think a lot of the hardened seat stuff is blown outta proportion. I mean.....these heads aint got hardened seats now. They ain't ever had seats installed. The seats look GOOD. I know they've had unleaded fuel run through them. I think people make too much of a big deal over it. The biggest enemy of valve seats is a dirty air filter. That's what causes valve seat recession. Dirt particles find their way through and chew the valve seats up like sandpaper. Generally, performance engines are some of the most well maintained engines there are. Unless you plan on your engine bein in a truck haulin heavy loads or something similar, I'd spend hardened seat money elsewhere.

 

[Garys1969RR]

Yea, now that you mention it, I have 9 sets of heads from 516s to 452s. All from recently running engines. And the only one with recessed ex seats is a 452 head came off a 400 in a motor home. And only the 2 center ex valves were recessed on that 1 head. The low amount of miles most of these cars see, I dont know if it pays to install hardened ex seats. And yes, 68 Coronet, I think those 902 heads are what you want. And they will work fine for you. I once read that all the big block head castings with the 1.74 ex valve flow within 3% of each other, in stock condition.( No Porting Done) Not sure if this is true, but probably pretty close.

 

[Meep-Meep]

For cruising around go with the most bang for the buck. If the hard seat 902's are good and cheap, use them.

It really depends on the metallurgy of the head if the exhaust valve seats will pound out or not. I have seen cases where the seats are sunk in a short time on a set of SBF heads that had no hard seats put in. I drove my own 302 Ford Mustang for 9 yrs and 95K miles with hard seats and no problems. I vote hard seats every time - either the factory hardened or the pressed in nickel alloy type.

 

[My1967GTX]

Why are you yelling? You asked if 902s will work in place of 906s. Yes 902s will work if they don't have cracked exhaust seats. You can use 250s, 906s, 902s, 346s and 452s for cruising around. If you want a little compression bump you can use 516s and 915s. Any big block passenger car head can be cleaned up and bolted on for cruising.

What is the "best" one? Everyone here will have a different favorite one. And everybody is right and everyone is wrong. Choose one and use it. You'll be right.

Sorry if you thought I was yelling,I wasn't, just wanted to "highlite" 'cause someone said run them "if that's what you want" and If I knew that I wouldn't have had to ask on this thread. I want to thank everyone for all the great info so that I can now make a decision. Thanks again all.

 

[Cranky]

I ain't even worried about hardened seats on these 516s I'm fixin to build. The car ain't gonna be 3400 pounds. It's gonna have either 4.30 or 4.56 gears. It ain't a truck haulin heavy loads, so the exhaust temp will be low. I think a lot of the hardened seat stuff is blown outta proportion. I mean.....these heads aint got hardened seats now. They ain't ever had seats installed. The seats look GOOD. I know they've had unleaded fuel run through them. I think people make too much of a big deal over it. The biggest enemy of valve seats is a dirty air filter. That's what causes valve seat recession. Dirt particles find their way through and chew the valve seats up like sandpaper. Generally, performance engines are some of the most well maintained engines there are. Unless you plan on your engine bein in a truck haulin heavy loads or something similar, I'd spend hardened seat money elsewhere.

Yea, now that you mention it, I have 9 sets of heads from 516s to 452s. All from recently running engines. And the only one with recessed ex seats is a 452 head came off a 400 in a motor home. And only the 2 center ex valves were recessed on that 1 head. The low amount of miles most of these cars see, I dont know if it pays to install hardened ex seats. And yes, 68 Coronet, I think those 902 heads are what you want. And they will work fine for you. I once read that all the big block head castings with the 1.74 ex valve flow within 3% of each other, in stock condition.( No Porting Done) Not sure if this is true, but probably pretty close.

I've never installed hard seats in any of my heads either. Actually, I've seen sunk seats in heads long before unleaded was ever introduced and have seen more damage done by installed hard seats coming out of the heads than I've seen from unleaded gas. If the job is done by a 'good' shop then things should be ok but then I've seen crap work come out of the so called good shops from time to time too.

 

[RustyRatRod]

The valve guide condition is also a huge factor of whether the seats stay in good shape. You're gonna hammer the seats out everytime if the guides are sloppy.

 

[69Bee]

Ok, induction hardened seats...

Induction hardened exhaust seats have an inconsistant depth, but Mopar are the best ones I have seen out there. I have seen SBC heads where the valve literally bored a hole into the head. Mopars are deeper from my experience, but that said, since the hardness thickness varies, you should put hard exhaust seats in when you rebuild the head. If a set of heads has already had one or two valve jobs, you are more than likely thru the hardness in spots anyway.

You guys spend a crapload of money on all other aspects of your cars, why would you shortcut your heads? I only charge $96 labor for a set of heads, and then the seats which will run around $4 to $5 each.

Once they are done, you won't have to worry about them again, unless you have some kind of failure, or the shop does not install them correctly.

There is a lot of mis-information out there about hardened exhaust seats. To tell you the truth, I would put hardened seats in all of my motors before I would put some of these trick suspension items, ignition items, cooling items, etc... The original equipment worked just fine from the factory, and still does.

As Rusty mentioned, one area I see people skip is replacing the guides. This is a sure way to destroy a good valve job, even break a valve head off. Do yourself a favor, replace the guides, and put in the seats...:grin: