how do the 305 vortec heads compare to the 350 vortec heads? im interested in them for my little 327 im building, they would put my compression ratio at right about 10.5:1. i just don't know how well they will flow with the 1.84'' intake valve. i want to run them with a lunati 00011 hydraulic cam along with an edelbrock perfromer intake. also will these heads accept Z28 type valve springs and LT4 retainers? if so how much lift will they handle?
thanks,
chris

anyone?

From what I know the 305 Vortec heads are similar to the non "Real" Vortec headed 350. Make sense? :D Probably not. In the early 90's GM started calling the truck motors Vortec. Be it a V8/V6 all were Vortec. (there is real 96+ Vortec V6 heads) The early heads are pretty much crap, they have a vane in the port which pretty much kills any decent flow.

The good Vortec heads are the 96+ 350 heads. From what I been told GM basically cast the LT1 head in castiron and put it on trucks. Which can't be the complete truth since the intakes won't swap and the Vortec have raised runners, so who knows but they work.

The 305 Vortec heads are just the older style, non real vortec heads. So they make good boat anchors.

Steve

Or paper weights.

well, the 96 Vortec 305 runs just about as strong as a 95 TBI 350- so they must have done something to those heads. i have a feeling they might be similar to the L99 4.3 heads used in Caprices- which makes 200hp and a fair amount of torque and moves a 4500 pound loaded Caprice around pretty good.
and, yes, the 96 and newer Vortec 350 head is essentially the cast iron LT1 head set up for a "gen 1" block- same ports, valves, and chambers, but with different cooling jackets and intake bolt pattern.
but, for a 327 with a 4" bore, i'd get the 350 vortecs and use a thin head gasket to keep the compression up and the quench nice and tight. it is a proven combo- they have been used with success on pretty much any small block engine size you can dream up already.