Soo, theres 062 and 906...
062 good... 906 bad ?
what are the diffrences ?
I just found out I have the 906...
How can they be made better ? expensive?

Thx for any info

 

I believe thier the same casting just made at different places.
Some better springs would be a good idea. Machine to fit dampners and machine for more lift. (depending on cam)
I think Scogin Dickey sells them for $419 a set.

 

I just read about them in CHP magazine.

The 906 heads were made for HD 3/4 ton trucks. They have a larger exhaust seat. That limits flow by about 20 cfm they said.

AJ

 

I guess a trip to the machine shop
will do some good

 

I just read the CHP magazine again and it said it's 20% loss of CFM, not 20 cfm. Sorry.

I guess that makes them worse even more.

I'm not sure if you have have the seats modded or not, but I'm sure a machine shop will tell you.

AJ

 

If you are going to machine those Vortec heads, you might want to consider another option... Edelbrock makes an Aluminum Vortech casting heads that flow exceptionally well and come complete for 1,000. Car Craft built a "spare parts" motor using those heads that made 540 HP! Just something to consider.

 

Your 906 castings may or may not have the pressed in hardened
exhaust seat..
If they don't, the head is the same as a 062 head. If they do
all you need to do is remove the exhaust valve and carefully smooth
out the bowl area and machined lip below the valve seat with a die grinder. Slim and trim and streamline the guide boss while your at it and polish the whole exhaust port. You do not really need to enlarge the port, just smooth everything.

Do this and you'll gain 20+ cfm from the stock head.

Go to http://www.chevyhiperformance.com/

Find the search button. Click on it and search for Vortec.
There is a ton of info there from past articles.

 

Did you see how rowdy that Isky cam was in that 540hp engine? I wish I had one laying around, with some 6" rods, or even the E-Tecs.

 

Why does chevy high performance call the vortec head "885"? I thought there was only 062 and 906. Somebody help.

Heres a link http://64.14.193.106/p104554_image_small.jpg