i was just wondering if any of you guys have had any experience with cj heads on a 390. i have a 1974 390 in my 67 ford. the motor was rebuilt by the previous owner. he put a different cam in it and id assume different piston. but any ways what could a guy expect for power gain if a guy puts cobra jet heads on and a aluminum intake and double pumper. or would i be better off getting a set of aluminum edelbrock heads. I know CJ heads have a 73-76 cc chamber. i really like the idea of putting cobra jet heads on. so i figured id see if anybody else as done it thanks.

 

There are a bunch of threads on this topic in the FTE forum: https://www.google.com/search?q=428+...w=1024&bih=543

You might very well find most of your questions answered in these.

 

okay thanks i tried using that search bar but i didnt find anyting

 

No problem. Tell us what you decide to do.

 

Do you have the heads yet?
C8OE-6090-N
The very early heads could be C8AZ -6049-K

A double pumper does NOT produce more power than a single pumper of the same size. It just squirts more gas to get off of idle and if you're not racing then you don't need it.
The 390 really doesn't need more than a 600CFM even with most of the usual go-fast stuff. I run a 650 spreadbore on my F250 428CJ, Holley dominator intake (it was free), small cam, headers (came with the truck), and dual exhaust.
I prefer the small bore primaries.
YMMV
What are you planning to do with the truck? How much are you willing to spend to get more power. Edelbrock heads run some $1500/set. They are pretty good heads but you can pick up some stock 427 heads for less than that and get good power.
As Smokey used to put it. Speed costs. How fast can you afford to go?