How about these heads?

[71chmark]

http://cgi.ebay.com/ebaymotors/Mopar-Ported-906-Big-Block-Heads-Cuda-Challenger-6-Pak_W0QQitemZ140240290039QQcmdZViewItem?hash=item140240290039&

Also a question 516 vs 915?

[bb71challenger]

http://cgi.ebay.com/ebaymotors/Mopar-Ported-906-Big-Block-Heads-Cuda-Challenger-6-Pak_W0QQitemZ140240290039QQcmdZViewItem?hash=item140240290039&

Also a question 516 vs 915?

Some 915's came with the 1.74 big exhaust valve.

[ntstlgl1970]

I wouldn't buy any rebuilt iron head sight unseen unless you know the machine shop or have a trustworthy friend who has used their services. $1200 is not a good deal on a set of rebuilt heads from an unknown source IMHO. You can buy new aluminum heads for less depending on what you want to do with your car.

[Super Blue 72]

Some 915's came with the 1.74 big exhaust valve.

   I think they were basically the same head, both closed chambered for increased compression, but the 516 always had the 1.60 small exhaust valve.

[ntstlgl1970]

the 915 head was a 67 only, 1.74 exhaust valve small chamber head. Some guys think they are the best non-max wedge head. Depending on your goals, I think putting large sums of money in iron heads, indy not included, is a waste of time and money.

[nivvy]

I wouldn't buy any rebuilt iron head sight unseen unless you know the machine shop or have a trustworthy friend who has used their services. $1200 is not a good deal on a set of rebuilt heads from an unknown source IMHO. You can buy new aluminum heads for less depending on what you want to do with your car.

how true............. I sold my fully ported 906's with the 2.14*1.81 manley severe duty valves for $850 with 10* locks  ..........   

i can get you a set of 915's totally stock for about 675 shipped....... but need worked .......

I would suggest searching for eddy aluminums for arount $1100ish worked over some....... save the weight ...... 

[Chryco Psycho]

if you are installing hard seats in the 516s go to 1.81 exhaust valves , now the only difference between the 516 is the 915 has smaller exhaust vales & the 516 is missing the hump on the floor behinfd the intake valve

[71chmark]

Since I have a stock low compression 440, with .284/.484 cam, would it really even be worthwhile putting on aluminum heads other than the extra weight? Will that bring me other problems such as my headers (Thorleys) won't work with angled spark plugs, etc.?
I just want something I can bolt on and go.  I'm not going to race.

[Chryco Psycho]

adding alum heads will effectively lower the compression some more as well

[ntstlgl1970]

Have you called around to see what it would cost to have your heads rebuilt locally? You could probably get yours done with hard exhaust seats etc. for half of what that ebay ad wants.

[71chmark]

I have the 346 heads and they need new springs.  They should already have hardened seats I believe.  I've heard the closed chamber heads are better with the 906 heads right behind.  I'm replacing the lifters and adding the 1.7 Roller rockers.  I figured I might as well upgrade my heads as well.

[bb71challenger]

Since I have a stock low compression 440, with .284/.484 cam, would it really even be worthwhile putting on aluminum heads other than the extra weight? Will that bring me other problems such as my headers (Thorleys) won't work with angled spark plugs, etc.?
I just want something I can bolt on and go.  I'm not going to race.

I think doing what Chryco suggests would really wake up that engine. Of course you need to find some 516's and should be able to for a lot less money than a worked set of 915's

[71chmark]

What will the closed chamber heads do to my compression ratio?  Will I have problems with pump gas? Do you think the 1.7 rockers will go with this?

[Super Blue 72]

What will the closed chamber heads do to my compression ratio?  Will I have problems with pump gas? Do you think the 1.7 rockers will go with this?

Closed chambered heads because of the smaller chamber in the head will effectively raise your compression.  Be how much, I'm not sure but possibly as much as 1 point, say 9:1 vs 10:1 ratio.  Off the top of my head, stock '67 383s with 516 heads were about 10:1 compression. 

Will it run on pump gas I dunno  , maybe someone else can chime in.

[Chryco Psycho]

you say you have a stock low comp engine now , do you know what the compression is , the closed chamber heads will raise coimpression aprox 1 point , piston tto valve clearance is alway an issue when going above .525 lift , you need to measure the clearance to see how far you can go
 by going to an Indy head for example with a 78 CC chamber you have increased the compression by 1 point & lost approx 1 point to heat loss to alum , by using iron 78 cc heads compression is bumped 1 point with no heat loss, by using Eddy 84 cc heads you gain approx .4 in compression & lose 1 point to alum so you are goign backwards