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Author Topic:   Need help with heads
Dixon
Dirt Full Roller

Total posts: 45
posted March 16, 2002 11:02 AM
I need help figuring out which heads I have. I checked out the toolbox, but I couldn't find these casting #'s in there. Head # GM 354434, and the only other marking (other than left and right) is H26 76. I know they came off of a 307, but I don't know what year. The block # is 355909, and I couldn't find that one either. The guy I bought the car from said the engine was out of a '68 Impala.
I just want to know what I have and if I can make any power with them. Thanks in advance for any replies.

BK19
Dirt Freak

Total posts: 285
posted March 16, 2002 11:25 AM UIN: 40696038
her you go
354434.....75-79...262/267/305...60cc chambers
355909.....262.....75....2
355909.....305...76-79...2

snowman
Dirt Maniac

Total posts: 140
posted March 16, 2002 11:44 AM
Dixon, I have no personal experience with either the block or heads.

According to my casting number guide,

the heads were used from 75-80 on 262-305 engines and had 1.84 and 1.6 valves with a 60 CC combustion chamber, but it is my experience that the CC listed in the book is not always right.

The block number was used 75-76 on 262 engine and 76-79 on the 305 engine, 2 bolt mains.

snowman
Dirt Maniac

Total posts: 140
posted March 16, 2002 11:49 AM
OOPS, Bk19 and I were posting at the same time. Sorry BK19. Second time thats happened to me. On the bright side, maybe my books CC number is right this time.

BK19
Dirt Freak

Total posts: 285
posted March 16, 2002 12:39 PM UIN: 40696038
snowman that has happened to me a few times also posting at the same time! no problem

Dixon
Dirt Full Roller

Total posts: 45
posted March 16, 2002 02:04 PM
Thanks guys! I guess the motor is a 305, it doesn't really matter, though. I wasn't planning on using that block. Snowman, I have a question about those valve sizes. You said they were 1.84 and 1.6. That's a strange combination, I haven't measured them but I would think that they'd be 1.94 and 1.5. I like the small chamber volume, but if anybody has used these heads please let me know. I don't want to spend time on these to find out that they're crack prone or something like that.

snowman
Dirt Maniac

Total posts: 140
posted March 16, 2002 09:23 PM
Dixon, I don't have any personal knowledge about these particular heads, I can't say for sure what the valve sizes are. The casting guide does list 1.84 valve for the head, I didn't make a typo there,if thats what you're thinking.

I can tell you chevy used the 1.84 for various heads. If you find the numbers I gave you are wrong, Let me know so I can note it in the guide. As I mentioned earlier, the guide isn't always right. Thanks

hughes
Dirt Maniac

Total posts: 141
posted March 16, 2002 11:06 PM
I wouldn't use any 305 heads for racing. Small combustion chamber= GOOD, But Has no flow which will= no power. Just the opposite of a 882, good flow (Smile), large chambered head= bad (no power). If your rules allow find a (old style intake) casting number 461, 462, 186, 187, 041, 292 head or for the new style head go with a 062, 906.

Dixon
Dirt Full Roller

Total posts: 45
posted March 18, 2002 10:56 AM
I was wondering if anybody knew the volume (in cc's) of the intake and exhaust ports on the #434 heads. I still might use them, because we all know flow can be "adjusted".

Dixon
Dirt Full Roller

Total posts: 45
posted March 18, 2002 10:57 AM
I was wondering if anybody knew the volume (in cc's) of the intake and exhaust ports on the #434 heads. I still might use them, because we all know flow can be "adjusted".

redneck bubbas racing
Dirt Freak

Total posts: 213
posted March 19, 2002 12:12 AM
I use a set of 601's(more 305 small chamber heads) on my 377 and they flow enough for it to turn 6300 so you should be ok. They are crack prone. Don't spend a lot of money on them other than a good valve job and you'll be happy with them. By the way, mine has 1.84 and 1.50 valves.

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