So i bought a Fully dressed vortec motor and of course the heads were cracked from a failed head gasket. I found a junkyard with vortec heads for $100 each. obviously i want the heads tested, cleaned and decked wich would be a total of $255. were puting in a cam that needs a lift of .520 so we would need new valve springs to accomidate it. Total price comes to about $355 per head. The debate is whether or not i should just get new loaded heads already equiped with the springs for around $500-$600 each. Or build the vortec heads for a little less and take the chance of the vortecs cracking on me. the motor build is very mild mind you.

 

It all about the details as pretty much everyone is going to say.Starting with block casting numbers at the rear of the engine,to are you intending to tearing down this engine for a re-build to what is a mild build in your mind to intended use.What trans,what rear end gears,what SCR,what DCR,what cam,etc.

 

To answer what was asked, first, starting with new GM castings doesn't guarantee no future cracks. Dart and others offer their own Vortec-configured castings that are less likely to crack. Also, most of those alternatives have ports that give up a little flow from 0.100"-0.300" lift, but don't stall above 0.475" lift. Still need to taper the guides and polish the exhaust ports, however. Most of them will still do better with a dual-pattern cam, also. Even if the cam is HR, 0.520" lift is not "very mild". Also, do you already have a Vortec intake manifold you like? If not, that adds to the cost of going Vortec. If money is tight, then forget the decking, get a lower-lift dual-pattern cam, and get a new baseline. A 20080543 Lunati HR cam is an excellent match to a stock L31 Vortec 350.