Cylinder Heads

[4x4Cowgirl]

Alright well I'm tryin to figure out what heads I have on my motor. The guy I got the truck from told me they were Corvette heads. So I'm looking for the casting number, and I can't find one that's anything like what I'm finding on the internet. The only numbers I can find is:

4B6
2D6
8345


That's all I got, Am I lookin in the right spot? Or how do I find out what kind of heads these are? 

[4x4Cowgirl]

nevermind lol i found the # under the valve cover LOL

[4x4Cowgirl]

But how do i know if they really are vette heads? im not findin that they are only says the valve size and yr

[Irish_Alley]

whats the number?

[Lt.Del]

www.mortec.com

[4x4Cowgirl]

I went to Mortec.com and it doesn't say Corvette or anything beside the stats... So I guess they're just stock smal block heads... Here's the number though: 3998991

[Irish_Alley]

well 
1970-76  350  1.72  1.5  74.56  or
1972-73  307/350  1.72  1.5  75 

3998991    307, 350, 75cc, 72-73, 73 had hard seats
they do appear to be vette heads they came on 68-76 vettes 307 or 350 but thats not to say other sb didn't use them, that being said they did come on vettes

[Captkaos]

I wish I had a nickle for every time I heard that line.  Even if they were Corvette heads, the ones in the smog years weren't nothing to brag about.

3998991 were 68-76 307-350 small valve (1.72/1.5) heads.  Definitely not off a Corvette.

[krazylunatic]

from what im seeing they are just stock chevy heads, nothing special

http://www.hotrodders.com/forum/3970010-block-3998991-heads-low-compression-motor-138756.html
http://forums.popularhotrodding.com/70/6678879/got-your-tech-right-here/which-heads-to-use/index.html

read some stuff on those 2 links and they are low compression heads so either he mislead you or he was mislead in believing their corvette heads

[eventhorizon66]

Sorry to hear that.  If you are serious about performance, those are gonna be a downer.  Find a set of good L31 Vortec heads, grab a Professional products crosswind intake #52028 (Edelbrock RPM Air-gap with $100 knocked off), and you'll be golden.

[Irish_Alley]

going by what they said i would have to say nope to the vette and what capt said with those numbers i wouldn't think they were that great of a vette head

[4x4Cowgirl]

Yeah I researched it for a long time and I found the same results. Even if they are Vette heads, they aren't anythin special. But I'm just goin to have to deal with them for the time being cuz I 'm on a tight budget lol. Just gonna take them to the machine shop today and get them rebuilt and cleaned up and repainted. I guess it'll do for now. I don't need anythin too over the top... Even though I may WANT it lol but thanks for the help guys! 

[Irish_Alley]

i bought a couple sets of heads off one guy and a motor. well it was only supposed to be the engine for i like 200, got to his house he used to be a mechanic and i guess he was moving cause he loaded my truck with nothing but Chevy truck parts, wheel trim, bed rails, a door or two, the engine, a steering column, dash clusters and accessory brackets then he handed me on set of heads he didn't say nothing about them i looked at them they were double hump heads put them in the truck then he handed me what he said were vette heads
3795896....63-65...283......60cc chamber
3795896....62-64...327......60cc chamber

[Captkaos]

3795896 aren't Corvette heads either.  Corvette heads would have 1.94/1.5 valves for the later years 75-82 and 2.02/1.6 for the Muscle Car years (pre 74).

[Irish_Alley]

thats what i meant when i said "he said they were vette heads" should of quoted that before
they look like this well the casting symbol does