engine heads

[BIG CHEVY]

ok.....long post. i got a 350 engine in my truck. i wanna experiment and learn about the engines part of our trophies as i can almost do anything to the rest of the truck... so i understand all of how an engine works but i dont know how new parts would affect an engine overall or which need to be working together the most.  all info is welcome and appreciated but i will ask 2 sample questions...

1. if i buy heads new like vortecs or something and bolt em straight onto my stock chevy 350.....what would happen?   (no other changes)

2. if i got a new set of good headers and just bolted em on(i have manifolds)......what would happen?       (no other changes) what if both?

as i say all info will help me but if i get heads and dont know that my average cam wont let em sing time is wasted...money is wasted.....just cause i didnt know. i read a lot of books and stuff on engines so im competent in understanding. but none of em tell u what others have screwed up and learned from personally. thats the real sweet knowledge. so thanks in advance......just wanna learn.

[ohio hab]

You didn't state what year 350 so I will assume a 87 or earlier. Their are many upgrades you can do. If the engine is sound, then I would add a of headers with free flowing exhaust, and aftermarket intake, like an Edelbrock Performer (2101), and an Holley 600. As far as cylinder heads their are many choices. For an Generation 1 sbc a cheap upgrade is a pair of G.M 64cc cast iron heads which I find around here ready to bolt on, for around 200.00. The other possibilities, are many with most companies for cast iron around the $400.00 to $700.00 range for cast iron. Cylinder heads really wake up an engine. As for a cam, for a street truck daily driver you want to look around a .450 lift and and 112 to 114 centerline. The cam is chosen based on rear gear ratio, convertor stall speed, compression, and operating rpm range. I am old school, and don't mess around with vortec heads. I know they are a great cylinder head, but, after market companies, have an comparable cylinder for the same price ready to bolt on.

[BIG CHEVY]

its a 79 engine. very basic. reliable. but some groups say its all about the heads. some say heads but u gotta change some small stuff. some say just buy some good headers for quick bump in performance.

heads dont really come with a sticker that says how much hp they give and i understand that. but i wanna flirt with a smidge of performance. how much would each thing help? that type of stuff. likei would go buy some heads and intake tomorrow....but what do i get out of it? do i just hope its strong? do i hope i didnt buy too much for compression? would i buy these heads only to realize they dont help at all unless i buy a certain cam to get them strokin? i want the poor mans power...or maybe middle class performance. boiling it all down.....i dont got enough money to buy every head and run it with every cam and every piston etc.how would someone like me learn without trial? is it possible?

also all the videos show the guys using a timing light on their motors. how would u ever do it with p.s. pump and water pump in the way?

[klaussk]

From what I have read, the gm 64cc heads are good heads and you can pocket port them yourself with nothing but a pea grinder and the right burs and sanding attachments. Theres a company that makes a really nice kit. Ill have to look it up. You can also either port your stock intake to match the head ports. Or just do the heads and a edelbroke performer intake manifold. And if you do heads Id say theres no point in not doing the headers at the same time. It would be antiproductive. But with a Good flowing exhaust, headers, heads and intake manifold you would definitely feel a big difference over stock. And you would get your moneys worth. But its hard to say exactly how much power you will get. If I were to guess id say around 40 to 45 at the ground top end power. But you would see the most improvement in the mid range of your RPMs.Some might say you will get more power than that.

[1980c10]

a 64 cc head is a good step foward, the vortech heads are even better(also a 64 cc head) because they flow better because of design. If you go with vortech heads; you will also need an intake and you'll need to use self aligning rockers(stock vortech is fine). headers will also help this combination as will a free flowing exhuast. after that you will want to properly tune your carb for the improved flow. You'll also be able to advance your timing because of these improvements.

In my opinion these improvement will make a serious improvement in performance. the stock heads have low compression and don't flow nearly as well as the newer vortechs.
simply put  if you want to have some power you need to be able to move the air and fuel in and out quickly. If you wanted to take this another step you may want an improved cam., from there the next step could be some flat top pistons to increase the compression ratio.

 

[TexasRed]

I thought vortecs preferred a little less ignition timing due to the efficient almost fast burn like combustion chamber?

[ohio hab]

Since the engine is a 79, and I assume stock, any cylinder head with a 64cc combustion chamber is going to help. Since you want number's, I am guessing based on my expierience and variable's with the combination so I will go out on a limb. Heads 40-70 H.P., intake 25 H.P, Headers are a must with any above upgrade. Any money spent on a name brand, or GM 64cc is well spent. Dart, Brodix which I prefer and use on my sbc's, Edelbrock, AFR, are maker's of good cylinder heads. ProComp are cheap and I will not use them based on reputation and local talk. They are priced nicely, but if you buy them I would buy them bare. For a poor man's cylinder head use a G.M H.P. head from the 60's or early 70's. Casting number's ending in 041,186,461,461x,487x, there are more, these heads are still out there, and can be had at a reasonable price. Money spent on a good set of heads is never wasted. Putting in a gear in a heavy truck also is never wasted money, a gear really wakes up a truck or car. Headers can add 25-40 H.P. P.m me with a phone number and I will glady try to help you, It's all about combination.

[jdhall144]

Be careful if you purchase older cylinder heads because by the time you go through them to freshin em up you couldve bought a new set.And some of the early camelbacks dont have accessory holes for bracketry.My .02

[1980c10]

I thought vortecs preferred a little less ignition timing due to the efficient almost fast burn like combustion chamber?

Yes, I run mine at 32 degrees advanced with the vacuum advanced hooked up.
With a differant head with my combination I would guess maybe 37.

btw,
what I am running is a 350 4 bolt main, 670 holley street avenger(re-jetted), edelbrock vortech intake,1" open phenolic spacer and stock vortech heads except a radius grind on the valve seats, mild street cam, flat top pistons, and headers engine dynoed at 393 hp@5400 and 432 tq. In my case I started with an engine block and put together what I thought would be a great street engine on a budget and from the advice of members of this forum.