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Purs · 06-23-2005, 11:46 PM

I had a set of those heads on my 402 chevelle and it ran great. They come with big oval ports and have open chambers that should be around 115cc's. If my info is correct they were GM's early version of the 781's (which I'm currently running on my 496

)

It all depends on what pistons you have that will determine whether you want open or closed chambered heads. If you have flat top pistons you are probably around 9 to 1 compression (maybe less) with those heads. If you put a pair of closed chambered heads on there you might jump up to 10.5 to 1 (or more).

If you are looking for the '69 model year heads for your '69 396, some of the head casting numbers to look for end with 215 or 840, which are both closed chambered. I don't know any open chambered castings numbers for that year, but mortec.com will tell you.

Good luck.

06-23-2005, 11:46 PM	#3
Purs Got Big Block? Join Date: Apr 2000 Location: West Texas Posts: 1,510	I had a set of those heads on my 402 chevelle and it ran great. They come with big oval ports and have open chambers that should be around 115cc's. If my info is correct they were GM's early version of the 781's (which I'm currently running on my 496 ) It all depends on what pistons you have that will determine whether you want open or closed chambered heads. If you have flat top pistons you are probably around 9 to 1 compression (maybe less) with those heads. If you put a pair of closed chambered heads on there you might jump up to 10.5 to 1 (or more). If you are looking for the '69 model year heads for your '69 396, some of the head casting numbers to look for end with 215 or 840, which are both closed chambered. I don't know any open chambered castings numbers for that year, but mortec.com will tell you. Good luck. __________________ "Experience is what you get when you didn't get what you wanted." Last edited by Purs; 06-23-2005 at 11:49 PM.