Help with headers...

[Spassmacher]

I'm rebuilding my 327 in my '67 C20 and I'm trying to pick the right heads. I going for a mild performance engine. Not bone stock, but not so high performance that it becomes a constant maintenance situation. According to the picture in post #22 of this thread: http://67-72chevytrucks.com/vboard/s...d.php?t=331657 I have a 462624 or 333882, not sure which, on one side. The other head is another type of double hump (I think) that I didn't see on that picture. I've heard a lot from some older fellas touting the benefits of the double hump heads, but from what I've read, vortec is the way to go. This is my first rebuild and I'd love to get some advice from the community on what would be a good performance head that won't cost an arm and a leg.

[67c10rustbuket]

You really need to pull a valve cover to look at the actual casting number instead of those casting marks on the outside of the head they're a little confusing, it is between the rockers. I think the 333882 was on 350 and 400 cid in the late 60s through the late 70s. they could be 1.72 intake valves or 1.94 i've had a set of both sizes(333882). obviously the larger is better. I have heard that the old double hump or camel hump heads dont have hardened valve seats so thats an extra cost at rebuild time, other than that they flow real good for a stock head. The vortec heads are supposed to flow better than those old double hump heads but there are a few drawbacks, they use smaller springs and as factory made can only handle up to .500 ? lift some sources say .475 but for a mild street engine thats fine you can get a cam with a lift within that range and a little longer duration to maximize flow. the other problem with vortec heads is you need a special vortec only intake manifold which is a bit more expensive than the older model. but ive seen quite a few used ones on craigslist for less than $100. the other difference is the old double hump heads dont have accessory holes so you will have to use the old long arm alternator bracket while the vortec heads have the modern accessory holes so you could use a v belt setup or a serpentine setup from an 88-98 truck or ?year car.i've also seen rebuilt vortec heads on CL for $300 thats pretty good for a performance head on a budget! I would buy some for mine but that would put my compression way to high but thats my own fault for chosing the wrong pistons so im saving for aluminum heads. your title should be help with heads, not headers. might get a better response good luck!

[Spassmacher]

Yeah I definitely meant to type heads, not headers. I'm an engine novice, but I'm not that green. I'm new to the forum, so if anyone can tell me how to change the title of the thread I will. I don't want to look like such a noob. I've got the valve covers off right now, so I'll get the casting numbers off of them tomorrow.

[67c10rustbuket]

You get the numbers yet ? your not a noob its easy to make a typo or brain fart. lol

[Spassmacher]

Yeah I got the numbers finally. Found out one head is the 462624. Researched a little and found that those were pretty much crap. The other head is a 14014416. I'm pretty sure I'll just go with vortec heads, and not bother with the camel hump malarky. Now I'm just trying to figure out if they will bolt to my 3892657 block, or if I have to do anything special there. I know when I shop for an intake manifold I'll have to keep the vortec head thing in mind. I'm not really sure what I need to tell the pro who's doing all the balancing and cam work. Once the discussion goes into cams and clearances and lift and all that, I'm lost.

[67c10rustbuket]

Originally Posted by Spassmacher

I'm pretty sure I'll just go with vortec heads, and not bother with the camel hump malarky. Now I'm just trying to figure out if they will bolt to my 3892657 block, or if I have to do anything special there. I know when I shop for an intake manifold I'll have to keep the vortec head thing in mind.

You dont have to do anything special, they bolt right up. Your block may have the old " blow by " intake vent in the back of the block under the intake though which if it is still there you can remove it and plug the hole as long as you use vented valve covers. I think the only time you have have to do anything special is when you have a 400 cid block as they need steam holes in the heads , so ive heard.

[67c10rustbuket]

Originally Posted by Spassmacher

I'm not really sure what I need to tell the pro who's doing all the balancing and cam work. Once the discussion goes into cams and clearances and lift and all that, I'm lost.

As far as balancing goes you can discuss that with the machinist. I told mine i will be using patriot performance aluminum heads with flat top hyp coated pistons and want it balanced to 7000 rpm to be used in a truck with a 4 speed m20 muncie and i want 400HP, not a daily driver but not a race car, and they will tell you what needs to be done and how much $ and what your options are. Usually once your discussing the plans for your engine you can talk about what cams they would recommend for your specific project also.

On my engine build the machinist weight matched the pistons (by removing a little material off the heavier ones) same with the rods, then they needed one set of rings, my crankshaft , ofcourse all the rods and pistons , the flywheel, and balancer. and had it all machined and balanced together so i can spin it up to 7000rpm. a lesser rpm engine may need less work. and a higher rpm needs alot more work and $ . but a good thing you have is a shorter stroke (your 327 3.25 stroke) can handle more rpm than a longer stroke (my 350 3.48 stroke) at any given level of balancing.

Make sure you use a compression calculator before you buy your pistons or you may end up buying the wrong ones that put your compression too high for vortec heads, and then you have to buy aluminum heads with a bigger chamber to lower the compression back into street friendly, pump gas range. Yes I did it, thats why I cant use the vortec heads. I bought the pistons as soon as I had the block bored out. oops , always wanted some aluminum heads anyway

[Spassmacher]

Awesome, thanks a lot for the tips. It's been great tearing down my first engine and planning the rebuild. Lots of info to digest, that's for sure.
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[406 Q-ship]

I would go with the vortec's, cheaper than rebuilding a set of early heads. Besides the performance of the vortec will leave the old school camel humps in the dust (unless you spend money getting them ported....alot). Becareful when buying heads that are claimed to be vortecs, they only came on GM pickups from 1996 to 1998, and GM large vans after 1996 till I don't know when. The 5.7 vortec head is slightly better than the 5.0 vortec. There are a few people who will try to pass off the old TBI head (CRAP head) as a vortec, the easiest way to tell is that TBI's have an exhaust crossover when the vortec does not. They are still available new from GM Performance parts or one of the many GMPP dealers (Scoggins). The Factory Vortec can only take to .485 lift or the spring retainer will hit the valve seal, Scoggins sells a modified head that will take more lift.

[MARKDTN]

Originally Posted by 406 Q-ship

I would go with the vortec's, cheaper than rebuilding a set of early heads. Besides the performance of the vortec will leave the old school camel humps in the dust (unless you spend money getting them ported....alot). Becareful when buying heads that are claimed to be vortecs, they only came on GM pickups from 1996 to 1998, and GM large vans after 1996 till I don't know when. The 5.7 vortec head is slightly better than the 5.0 vortec. There are a few people who will try to pass off the old TBI head (CRAP head) as a vortec, the easiest way to tell is that TBI's have an exhaust crossover when the vortec does not. They are still available new from GM Performance parts or one of the many GMPP dealers (Scoggins). The Factory Vortec can only take to .485 lift or the spring retainer will hit the valve seal, Scoggins sells a modified head that will take more lift.

What he said. Vortecs are the way to go. If you have double humps, sell them for their historical and collector value. By the time you do the right machine work on a set of old heads, you can probably buy the Vortecs.