Head questions? would 3782461 heads work well on my 307?

[kevinmfduane]

I have a 307 in my 82 shortbox. I want a little more performance out of it. I have an edlebrock intake and carb, headers, and a mild cam. I want to upgrade the heads next. I have found a set with casting 461 and I am wondering if it is worth getting the heads rebuilt (valve job) and if anyone could recomend what machine work should be done to these heads. I have never swapped out heads and am not sure of the cost involved. Can anyone help me out here?

[softballnrd27]

3782461....64-66...327......Camel hump,no accessory holes,160/62cc port volumes,62cc chamber
That is the info from mortec. You will probably have to have the accessory holes drilled and tapped depending on what you have mounted and how you have them mounted. If you had the casting number off of your heads on the motor now it would help some as well. Most of the heads that came on a 307 have 70cc to 75cc combustion chambers. The heads you listed are 62cc combustion chambers so your compression is going to go up at least 1 full point. For example with my pistons (-5cc dish) with 76cc comb chambers I would get 9.4cr and with 64cc comb chamb I would get 10.7cr. So you can see the amount of compression I would gain by going to 64cc heads. Since they are iron heads and I want to run on the street I am going to stick with my 76cc chambers.

Now, to rebuild your heads, a good valve job can be $100-150, you will also need to get them magnafluxed to check for cracks before you do anything. Find some good stock springs/retainers/locks and seals and you should be good to go. Look to spend about $300 maybe.

[kevinmfduane]

Thanks softball. Where can I see the block casting number if the engine is in the truck? I have power steering but no AC, so I hope the accesory holes will not be a challenge. Since 307s were an economy motor with 283 bore and 327 stroke// and the 327 that these heads came off of was a factor performer// does that equate to performance on my engine once I have them rebuilt?

Thanks

[kevinmfduane]

Even if my compression goes up a whole point over the factory 307 specs will I still be able to use 87 octane?