[Gregski]

Originally Posted by Skunksmash

My old truck just needs more power. Its not gutless, but its pretty far from great too. So I've got a few questions regarding upgrading the cylinder heads on my 1987 Silverado 5.7L. It has the stock engine. I'm looking to just bolt on a new upgraded set of heads (and maybe a few other necessary parts) and leave the stock bottom end. Not looking to pull the engine out or anything like that.


1. What are the best possible bang for the buck heads that will fit my 87 350, that are cast iron? Please be very specific because I'm not real familiar with this topic.

GM Chevrolet Performance Vortec cylinder heads ($50 bucks each used pulled from 1999 Chevrolet Suburbans at the junk yard)

Originally Posted by Skunksmash

2. What are the best bang for the buck heads, that are aluminum?

Blue Print by far best bang for the buck

H8002K - Heads - 195cc SB Chevy Head

Originally Posted by Skunksmash

3. Is there any reason I should buy aluminum instead of iron?

better cooling properties, pros / cons (lighter on your hands / heavier on your wallet, lol)

Originally Posted by Skunksmash

4. What kind of power increases can be expected from both sets? I assume that by now, that should be pretty well known by the 350 community.

as they say how much do you want to pay, you can spend crazy amounts of money to pay a machine shop that knows what they are doing to put bigger valves in pretty much any decent iron heads and port and polish them and make them 400 HP heads, it takes many many other components to deliver a total package, cam, rockers, pistons, carb, exhaust, etc.

visit the Chevrolet Performance website and select Small Block engines, you can sort them by horse power, torque or size and start clicking on them one by one then look at their output and read their specs, they list every part that goes into building that engine, even if you don't buy GM, you can see what the cylinder head specs were, or the cam specs, etc.

here's a chart for an engine called the 350 HO TURN-KEY with Vortec iron; 64-cc chambers Cylinder Heads (P/N 12558060):
Camshaft Type (P/N 24502476):Hydraulic flat tappet
Camshaft Lift (in.):.435 intake / .460 exhaust
Camshaft Duration (@.050 in.):212° intake / 222° exhaust

Originally Posted by Skunksmash

5. What other parts should also be bought at the same time, to maximize the potential of the new heads? Don't want my old stock parts to be choking them out and hindering their power somehow.

Cam ie Camshaft anything with 1/2 inch or less is a good cam for a street daily driver (1/2 inch in cam specs is .500 or less valve lift), after that your vacuum will be too low and your truck won't idle smoothly or good

this is street car recommendation not weekend warrior at the drag strip

Originally Posted by Skunksmash

6. Is there anything else that you think I should know, regarding such an upgrade? Please keep in mind that I just haven't dealt much with these old 350's. Aside from standard maintenance and just replacing consumable parts like spark plugs and distributor caps and oil pressure sending units and the like. Most of my work in daily life, is all done on modern engines, usually 4 cylinders like hondas and toyotas and such.

Watch out for the domino effect, sometimes when you change heads you will need new valve covers as there are two kinds, center bolt and outside bolt

also some heads (like the Vortec ones) have a different intake manifold angle and therefor require a special Vortec style intake manifold

and as always where do you stop, ok so you bought heads and a cam, might as well get new lifters, or do you? might as well get new push rods, or do you?, might as well get new rockers, or do you? hewk got a new cam so might as well replace the timing set (chain and sprockets) or do you? well since we took the water pump off to get the cam out no sense in bolting the old still working water pump back on might as well get a new one, or do you? etc. etc. etc.

put a plan down on paper with a budget, six months later when you are done, see how you've done