Big blocks all ran the same heads. There were pretty much only a few substantial design differences between the different kinds of heads. 906's are no better than any other of the open chamber big block heads. Some would argue they are worse than the 70's heads because at least the 70's heads came with hardened valve seats. Doing head work or picking up a set of aftermarket heads is always a good idea. Flow is flow, so better flowing heads will make more power with a given cam.
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The cam I'm looking at is a Comp 21-223-4 I think. Is this too much for a stock 2bbl motor which now has a 4bbl setup?
That cam is the XE268H. Don't call it the 21-223-4, most people don't know off hand what what means, but the letter/number cam grind designation for comp's line of cams is much more familiar to most than the part #.
268H is about the most cam I would want to run in a street 383. It'll be a great street/strip cam with a lopey idle. Do a search, some member posted a vid of his 383 with the XE268H a while back. If it's the 4sp car in your sig that this motor is in, and you have 3.55 or numerically higher rear end gears, IMO this will be a good cam for you.
