BB heads 645?

[sundrop_440]

Has anyone heard of this casting # for a 440 and how do they compare to 906,s or 915,s I hope you can help thanks

[23T]

My book does not list that #. You sure it's right?
the 600# heads I show are 622,635 & 676

[sundrop_440]

yeh that's the # this guy gave me I'm interested in buying them if they're agood head. Do you know if any of the 600,s flow good

[23T]

Alll I can tell you is # one find out what # the heads are you are trying to buy, That # is wrong I think as far as the 600# I gave. the 676 is 71-77 361 truck/361 marine/413, 622 is 58-60 350/361/383 & 635 is 58 350/361 D500 & similar the last two have 1.94" & 1.60" valves

[b-1ken]

Assuming you have 1.74" exhaust valves, there isn't much difference in the flow numbers regardless of the casting number.
Basically, all stock B heads flow like crap.

[dave571]

If 23T is right, those are industrial heads

They are completely different than passenger heads.

Industrial heads are not made for performance at all, and after seeing as set, I don't think they would even fit on a passenger block. If they would, passenger manifolds certainly would not.

In short, they are completely useless. Unless you're trying to build something for pulling houses down the interstate, or something.

[sundrop_440]

I apprecaite all your help it didn't make sense to me either I have a e-mail back to this guy to have him double check the casting # I saw pictures but who knows maybe it's a wild goose hunt but thanks for your help you probably saved me from a big mistake. Special thanks 23t

[23T]

No problem that's what everyone's here for, to help each other.
Keep us informed on the heads, I have bought some and the shipping is about the same price as the heads.

[6 packin]

I bet is not seeing the last number 2 which means 452's. If your lucky, those are the best heads in my book. Flow very well, and have harden exhaust seats for unleaded gas.

[AndyF]

If you can't find any heads in your local area then shoot me an email. I have stacks of factory heads sitting on my shelf. I need to get rid of some of the them before the shelf collapses!

[jelsr]

If the pictures show the ex ports check the bolt pattern. If they are the ind/truck heads the bolt pattern is not "all in a row". The end ports bolts are staggered. Should be 7 digits in the casting #, and according to the last article I read that had flow rates the late castings were all about the same, very small difference from the 906 thru the 452. Main thing was the hard seats in the '74 and up heads.

[sundrop_440]

the picture I saw showed the# 0645 I'm going to see if he is looking at the wrong #'s Thanks for all this help

[sundrop_440]

say AndyF I couldn't fly you an e-mail through this site if you want contact me at sundrop_440@yahoo.com

[23T]

I bet when you get the whole # it's 4006 452, good heads 2.08 & 1.74 valves hard seats. I'm in the process of P & P a set right now to go on my 400.

[sundrop_440]

say 23t or anyone who knows the answer, if I picked up a set of 452's can I enlarge the hardend to accept 2.14/1.81 without concern or are those seats just surface hardend

[23T]

I'm going to have the larger valves with 4 angle grind put in my heads + cut .06 when I'm through. My shop said no problem and they O track Mopar's.

[sundrop_440]

Well guys I finally got it straight or he did I should say he was reading the wrong #'s on the cast I re-directed him and he sent me another photo with the right #'s (452's) I have 906's now But I run mostly on the street and I thought I might save some money if I didn't have to install the seats if Igot some 452's I'm going to p&p them and install large valves myself now we have to agree on price so we'll see how it goes Thanks again you guys!

[sundrop_440]

Well guys I finally got it straight or he did I should say he was reading the wrong #'s on the cast I re-directed him and he sent me another photo with the right #'s (452's) I have 906's now But I run mostly on the street and I thought I might save some money if I didn't have to install the seats if Igot some 452's I'm going to p&p them and install large valves myself and mill them to get my comp. up but first we have to agree on price so we'll see how it goes Thanks again you guys!