have 74 350 out of a Monte Carlo.  Nothing special at all.  165hp factory California engine.  Its in my 65 Chevelle for now just to keep it running while I fix everthing else up.  Well It needs a valve job b/c it wants to run on leaded gas.

I have a set of vortec heads off a 97 305 truck.  The cast numbers are 12558059.  I know they have 1.84/1.5" valves.  Only thing is I find differing combustion chamber size. Either its 58cc or 64cc. 

Does anyone know exactly what it is?  Can the valves be machined larger to 1.94"?  Given the fact that they are 64cc and I can machine the valves to 1.94" would this head be comparable to the 350 vortec head?  Reason being can I install these on to my 350 for now and in the long run when I start building the 350 still be able to use these?

Thanks

Sure can...theyll work fine and theyre a cheap easy way to grab some compression points.

1.94's are a good street size valve IMO...better low end and TR....plus theyre a dime a dozen...or eight.

With the 64cc chamber theyll accept 2.02's...but Im not sure if the actual 305 heads had a smaller intake runner than the 350..probably not....so Id say USE EM!! and say hello to Mr. Throttle response!!

Some of the other 305 heads are limited on valve size because of the small chamber plus the fact that they wont accpet a bigger valve into the small 305 bore...but youre probably not worried about that.

I dig the modded stock head thing, I too am running a set of 305 heads...mine arent vortec's but theyre the HO 58cc chambers.

Too bad they dont have a victor or a team G intake that'll fit the Vortecs.

-Shred

real vortec heads came on 350's not 305's. Sorry.

When I ran the serial number it said it was a vortec.  Also the 305 it came off of used the same intake manifold as the 350 vortec. So is there a different place I can run the number to find this out?

all depends on what you call "vortec".

SOme people say that heads that are centerbolt valve covers are Vortec, some say its the intake bolt pattern difference.
Some say its the chamber design...yada ya.

People argue about whether or not 305 heads can be Vortec...
But I dunno if they can be or not....but 305 heads CAN be center bolt, Triple bump castings with the different intake pattern.

so i spose i shouldnt have said anything....anyone care to actually explain the differences?

-Shred

a true vortec head has 4 intake bolt holes that go straight down into the head, and a very distinct intake runner shape.  I also believe the spark plug hole is closer to the exhaust port than the intake.