[JHayman2677]

Before anyone gets frustrated at me, I have already went through the knowledge base and it just confused me more.

OK, I'm trying to identify the heads on my sbc 400, so I was looking at the pics I have and compering them to the drawings in the knowledge base. At first I thought they where 350/300 hp heads that are relitivly rare, with 1.94"/1.50" valves and all. I was useing this figure to try to figure out what compression ratio my engine is at.

Well, to make a long story short, the casting #'s on the heads, say they are 305 heads, and the stamping on the ends say something else. I was just seeing if anyone could give me any ideas as to why, and maybe some tips on what I should do?? Any help is greatly apprecieted, THANKS!!!

Here's a pic of what the ends of the heads look like. The casting # is 462624.

[firestone]

I looked up that number on the website below, look under small block casting numbers to find your head.

Adam

http://www.mortec.com/castnum.htm

[JHayman2677]

Originally posted by firestone
I looked up that number on the website below, look under small block casting numbers to find your head.

Adam

http://www.mortec.com/castnum.htm

Ok, I went to that site, and looked it up. But, it says different specs than the knowledge base here. What could be the reason?

Thank you very much for the help!

- Jason H.

[machine shop tom]

I checked a set of heads in the shop and also checked with MorTec. They both agree that they are 350 heads. (I haven't seen them with steam holes, which isn't to say there aren't any with them). They are not 305 heads. The marks on the heads resemble the 041 casting which is what the 350/300 heads were. They will measure around 76ccs.


tom

[JHayman2677]

Kewl!! So they are 350/300hp heads. Thanks a million for the info, you don't know how much I appreciate that! This has been bugging me for the last week!

Thanks Again!

- Jason H.

[machine shop tom]

You misread me. The marks RESEMBLE the 350/300 head markings, but they are not the same head. The 350/300 heads have 58cc chambers (give or take a cc) but your heads are more like 76 ccs.

[Goldduster360]

624 castings are lightweight castings, most have 1:94 intake valves, corvettes got these heads too with 2:02 valves. It is a smog head and has at least 76cc chambers. It is even lighter duty than the 882 head casting. 624's and 882's have irregular shaped intake ports that cost horsepower. You can still make good power with them though.

Inspect the heads carefully before spending any money on them. If they need guides and valve work look for something better as you can find these heads as new take off's on ebay for cheap.

S/R torquer heads would be money better spent over dishing out cash on overhauling 624 castings.

I have a brand new pair of 624's(hecho en mexico) that are going onto a 383 mild build up for a daily driver. If the engine doesn't run high compression, run super lean or get overheated they will be fine. Too bad gm stopped putting the 993's on their base crate motors, they were touted as one of the best smogger heads with a heavier casting and better flowing intake ports. If I hadn't got these 624 heads for almost free I wouldn't be using them either.

Make sure you don't have a 642 head which was a truck head, most if not all came with 1:72 intake valves, heavy casting though.