i have never swapped them but i have owned two chevies with 350s. one vortec and the other not. the difference is most definately vERy noticable. granted, the 96 had CSFI instead of TBI, but vortec heads flow much better
thanks for the feed back the motor that the heads are going on is a 90 model out of a chevy truck it has been bored 40 out and has a 470 lift cam with new every thing
except block, crank and rods all recon. Im puting it in my 1986 k5 and im trying to get around 350hp any ideas on how much power this motor should have also i'm runing 1 5/8 headers and a road demond carb. [img]images/graemlins/40BEER.gif[/img]
.470 lift is very close to coil bind on stock vortec heads. I've installed vortec heads on a couple differnt engines, and used Crane springs with a cam lift of only .450. The performance of the Vortec head is very good, when the price is considered.
These heads where bought out of jegs new but i was worried about this same thing so had them check but the engine shop they said they would be good up to 485 lift
they also made the cam there i also had the engine balnced by them but the reason i asked about the hp is they told me
that this engine would be around 310hp or so i wanted more like 350 to 375hp.
The vortec heads flow a lot better, but like what was said before, make sure you got good valve springs, if ya want to run that much hp. Spend the extra dime on those and rod bolts. Before you put the heads on, put your exhaust gasket on and cut out the head to match, you can do this with a die grinder or good dremmel tool. Gasket matching the exhaust should give another 25 hp and is easy to do. Make it breath.
Thanks for the tip. I really want to on lock all the power in this engine. so i'll try anything to get it. the reason i ask so many ???? is that i'm new to small block i have always run big blocks but thanks for the tip. [img]images/graemlins/40BEER.gif[/img]
I think you might want to reconsider the springs. Let me say this, the difference between .470 and .485 is only .015. Now lets compare the average gap of a spark plug about .045. That means .015 is only 1/3 of the the average gap of a spark plug! I really want to stress the point, do not use stock springs with a cam that has .470 lift. It's just going to plain suck, when you break a push rod, or even worse, suck a valve into you engine. [img]images/graemlins/frown.gif[/img]
[img]images/graemlins/goodpost.gif[/img]After reading your post i did some checking and found out that it is not much more so i'm going to get a set of z28 springs put in them and some screw in rocker studs does any one have a set have self algi roller rockers cheap?
thanks a lot dave [img]images/graemlins/40BEER.gif[/img]
The junk yards are full of cheap self aligning rocker arms. All the Chevy 305 & 350 engines that have the center bolt valve covers (usually 1986 and newer) will have self aligning rocker arms. Just remember the keet the rocker arm and ball together as a set. I use a coat hanger to slide the rocker arm, ball and nut to keep them as a set.