any benefit to swapping 915 in place of 906's

[black71]

Just wondering if the closed chambered heads would make enough difference to make it a worthwhile swap...stock 70 bottom end and engle k58 cam

[Cooter]

Depends. The 906 heads have a larger exhaust valve if the "915" heads aren't the ONE YEAR ONLY 1967 GTX 440 Magnum heads that were closed chamber. However, the closed chamber of the 915 will definately help compression. This was the hot ticket back in the day when these engines were like the new Hemi today...Most "915" heads today are the "LP" version with the 2.08 In. And 1.60 Ex. valves.

[Chryco Psycho]

IMO definatly , the flat top piston needs to be close to the deck to be optimum , but it will bump the compression & kill the detonation common with the open chamber heads , 516 had the smaller exhaust valves , 915 & 906 have the 1.72 exhuast , I usually instally the 1.81 valve

[mopar12372]

it is smart to run a tighter quench with a closed chamber . like he said good call

[black71]

So if they are smaller exhaust valve heads, what's an appx cost of getting the larger ones installed

[Challenger6pak]

That depends on a few factors.  You can use the exhaust valves from the 906 heads, if they are all good.  Most of the time they are all good.  A machine shop will have to cut the hole larger and then do a valve job on the exhaust side.  Depending on the heads overall condition you may just want to do all the valves in the 915.  Depending on what needs done will determine your cost.  Your local machine shop should be able to give you a price on things.  Last valve job I had done was $15 a valve. It is a worthwhile endeavor even if you need a few valves and a complete new valve job on the heads.

[Strawdawg]

nice to get new seats that don't require leaded gas as well when the larger valves are installed

[Chryco Psycho]

To me small valve heads are a Bonus as stated above , have them cut for hard seats & install new valves , either 1.74 factory or the bigger 1.81 which I always use

[mopar12372]

those heads work very well

[Cooter]

To me small valve heads are a Bonus as stated above , have them cut for hard seats & install new valves , either 1.72 factory or the bigger 1.81 which I always use

Hate to do this Chryco, but don't you mean 1.740 Valves?

[Moparal]

Yes he does

[Chryco Psycho]

Fixed Thanks ... brain fart

[black71]

             so a set worth $150?

[mopar12372]

redone for a stock type set up i would say yes . used  hell they where 50$ when i bought them as cores

[black71]

So basically I am looking just to get my car going, trying to make the best of thigs right now, limited on funds like all of us....so I found a set of 1.6 ex valve heads, said they need gone though for $150...is this gonna be a worthwhile endeaver or should I just hold off ...honestly I jus want to maximize...I have a 543 stroker kit that I will be in the market for indy's at a later date...but am thinking the 915's right now just to get me up and runnin..my 906's need a full valve job and the guides are loose in my 452's