I have looked at some small block chevy sites about this and cant get the cc's from any of these.The heads are 462624 can any one tell me this and if these are any good heads.I'm not building a drag car but would like to have a little ass behind my ride and see if these are good enough or worth it to redo.These are on a 400 small block Thanks

Don't know much about them but they are 76 cc heads. Look here.
http://www.mortec.com/castnum.htm

I've pointed this out several times before here and let me cover it again.
Starting with the 1975 model (fall of 74) Chevrolet began cutting corners on the SB heads, such as the 462624 head. They were lighter, thinner castings, had an additional exhaust crossover passage (more heat) in the center of the head. Consequently, they are MUCH more prone to developing cracks, or developing them sooner, than the 1974-earlier heads. ANY 1975-later (with a date code of around Aug 74-later) PRODUCTION SB head is a lesser desireable head. I'M ONLY REFERRING TO PRODUCTION HEADS, NOT CHEVY'S OVER THE COUNTER PERFORMANCE HEADS, SUCH AS BOWTIE HEADS!
I hate to be the bearer of bad news, but you asked. If you choose to use these heads, BE SURE TO HAVE YOUR MACHINE SHOP THOROUGHLY MAGNAFLUX THEM! If they have no cracks at this time, do not be disappointed if cracks develop soon after you put them into use.

The 624 heads are among the worst of the worst. Don't bother spending any money on them. As already referred to, they are highly prone to cracking in critical places, and do not take kindly to port work as a result; their combustion chambers are a cavernous 76cc, and leave you with a compression ratio way short of anything resembling performance; and their flow..... well, they're part of the formula for building 180 HP 350s and 185 HP 400s because they're so restrictive.

Please have them melted down for their scrap iron as soon as possible. Do your part to erase this disgrace from the collective memory.

Get a set of old double-humps such as 186, or F-body iron L98 castings (083), or even Vortec heads. All of those are 64cc, and will work well on a stock 400 short block with dished pistons.

A couple years ago I was looking for a cheap set of heads to just get my car running.. I had 2 sets of 624's myself.. Checked em out all 4 heads were cracked. I then found another set at the shop.. both of those were cracked.. And I found one last set at a friends.. guess what?? Both those heads were cracked too.. They all ended up in the scrap bin. Pay very close attention to the exhaust seats. All of these heads were cracked through the seats.

As mentioned above,melt those heads down in the form of a small boat anchor,& sell the anchor on ebay. graemlins/clonk.gif

I switched from 624's to Dart IE 180's, and gained .75 seconds and 5mph in the 1/4 mile. 624's aren't very good heads.

I am glad that i put this topic about the heads on here before i put money in these.I would like to say thanks to all who awnsered. I guess these will taken off and replaced.Once again THANKS ALL TOM graemlins/beers.gif