350 heads on a 305 ci
#12
05-28-2010, 12:09 PM
Join Date: Oct 2007
Location: The 'Burbs of Chicago
Posts: 18,306
The casting numbers are on top of the heads, under the valve covers.
Then you can look them up here: http://www.chevy-camaro.com/chevy-ca...es.asp?group=1
and here: http://www.mortec.com/castnum.htm
Here's something to read about the 305 heads, cam, etc.: 305 Head Tech
Then you can look them up here: http://www.chevy-camaro.com/chevy-ca...es.asp?group=1
and here: http://www.mortec.com/castnum.htm
Here's something to read about the 305 heads, cam, etc.: 305 Head Tech
Last edited by Camaro 69; 05-28-2010 at 12:12 PM.
#14
05-28-2010, 12:14 PM
Join Date: Mar 2009
Location: Tokeland, Washington
Posts: 21,671
heres some stuff from the thread that nobody read. 
u want castings that end with either 081 or 416.
305 heads are all cast iron and have combustion chambers around 58cc with valves that are as small as 1.74/1.50 (early heads) and as big as 1.84/1.50 (later heads). They could be had in either the early style 86-down bolt pattern or the later style 87-up bot pattern depending on year and application. If they use centerbolt valve covers then they have the 87-up style intake bolt pattern. They can be modified to take a larger 1.94 intake valve but the ports are still slightly smaller than any 350 head, at least on the intake side, and the valve centerlines are slightly closer together to fit down the bore of the smaller 305 engine (which is wy 1.94/1.50 is about as big as you can go with them).
u want castings that end with either 081 or 416.
305 heads are all cast iron and have combustion chambers around 58cc with valves that are as small as 1.74/1.50 (early heads) and as big as 1.84/1.50 (later heads). They could be had in either the early style 86-down bolt pattern or the later style 87-up bot pattern depending on year and application. If they use centerbolt valve covers then they have the 87-up style intake bolt pattern. They can be modified to take a larger 1.94 intake valve but the ports are still slightly smaller than any 350 head, at least on the intake side, and the valve centerlines are slightly closer together to fit down the bore of the smaller 305 engine (which is wy 1.94/1.50 is about as big as you can go with them).
Last edited by craby; 05-28-2010 at 12:16 PM.
#15
05-28-2010, 12:17 PM
Join Date: Oct 2007
Location: The 'Burbs of Chicago
Posts: 18,306
I read it, and answered your queries. Are you including yourself since you said "nobody"? 
#19
05-28-2010, 01:44 PM
Join Date: Oct 2007
Location: The 'Burbs of Chicago
Posts: 18,306
You are referring to the 350 and not 305 Vortecs?
And don't forget then, that a new Vortec style intake manifold will need to be purchased too.
So, how much of his money have we spent so far?
And don't forget then, that a new Vortec style intake manifold will need to be purchased too.
So, how much of his money have we spent so far?
#20
05-28-2010, 01:57 PM
Join Date: Sep 2007
Location: Lima, OH and Ft. Lauderdale, FL
Posts: 1,143
If you can get a good enough deal on a set of Vortecs, the $160 for an intake is well worth it IMHO, unless you're running a huge cam where you might run into problems (ask me how I know
) but this is the case with pretty much all stock heads.Luckily I think I have my valve train geometry figured out pretty well, it wasn't as bad as some people make it out to be.