|08-24-2010 10:12 AM|
|08-24-2010 07:13 AM|
|08-23-2010 10:31 PM|
|frodin1||It's kind of hard to tell from the pics, but they look like inserts.|
|08-23-2010 08:03 PM|
The 906 can have the hardened inserts. You can tell them by looking- the head has to be off the engine so you can see the seat. It also helps (but isn't absolutely necessary) to have the valve out as well. That way you can judge how bad the "lip" is that is formed by the seat insert.
INDUCTION HARDENED SEAT
So, judging by what you now know, can you make a guess as to what the next photo shows?
INSERT OR NO INSERT?
|08-23-2010 07:14 PM|
According to the threads that were posted: The L31 Vortec comes in two different casting numbers, 10239906 (#906) or 12558062 (#062). Originally, the stock #906 casting head was available in two versions. One version had an Inconel exhaust seat with single angle valve grind and was available on 1 ton trucks. The other version was the traditional three angle valve grind. Other than that, the #906 is the same as the #062 head.
The only thing I would like to do, is find out how to tell the difference without knowing what vehicle they came off of? Is there a noticeable difference by looking at them?
|08-23-2010 10:55 AM|
it goes both ways, some will say the 906's and some will say the 062's i belive it was the 062's that were used in the heavy duty trucks and had the hardend exhuast seat which is what nobody seems to care for but if you have had them rebuilt i would ask if they ground that down as many rebuilders will do. i personally believe you wont go wrong with either head. one motor i have had in the past had 906's on one side and 062's on the other and you couldn't tell any difference
|08-22-2010 04:21 PM|
Some handy links included.
|08-22-2010 03:18 PM|
|frodin1||I got it, I went through the links and found the explanation of the correct heads to use. Thanks everyone and I will keep tabs on my build!|
|08-22-2010 03:04 PM|
|frodin1||yea, I passed on it. I wished it was a 5.7. This thing had everything on it as well, A/C compressor, alternator, harness, Everything. But I found a thread on here that explained the major differences on the 305 heads. I'm just going to keep searching for what I need. Question: Which is better, the 062 heads or the 906's? I did find a place selling both "rebuilt of course" at a decent price, but don't really know which is better. I haven't had the time to read through the descriptions of them yet.|
|08-22-2010 02:52 PM|
these heads would work but they are not the vortec heads that we are talking about, i dont know as much about these heads as i do the 70's and 80's 305 heads but i doubt that much changed. the older model heads had from 58-60cc combustion chambers which some have used to raise the compression on there larger small blocks but i personally would never do this as the 305 heads are not meant to flow enough to make good power out of a larger motor. if you were to use these heads the motor would pull decent to about 4000 rpm but after that it would begin to fall on it's face.
IMHO these are not the heads you are looking for at all
|08-21-2010 06:11 PM|
|frodin1||Fyi its a 99 motor?|
|08-21-2010 06:02 PM|
|frodin1||Hey, I was wondering if anybody could clue me as to what heads are on the 305 motors? If these, heads would work? I found a 5.0 with 48K on it. absolutely complete for $300. But I don't think these heads will work for my setup? I'm guessing its the bore size and everything? Let me know, thanks.|
|08-20-2010 12:49 PM|
|my87Z||i would check compition products out too, they are kinda a racers secret but they are getting bigger and bigger every year. they typically have chaper prices on most of their stuff than almost anyone. i always check them first|
|08-20-2010 11:18 AM|
|frodin1||It's actually the same part numbers from Summit,and a tad cheaper. Not to shabby!|
|08-20-2010 11:07 AM|
I don't know if anybody knows what the crossover part numbers are, but I contacted KB performance about the 142 pistons. Their reply was this: The KB142.030 sell for $334.08 for a set of eight direct from the factory.
Check with Summit Racing 800-230-3030 or Competition Products 800-233-0199
for better pricing.
I gathered from this that maybe they are a wholesale only outfit?
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