Hey guys, last summer I picked up an LO5 350 motor from a yard. I swapped that into my '85 iroc and moved the stock TPI unit over as well. I also added a larger cam. Soon I will be putting a new computer/chip in because the '85 ECM is slow. I'm trying to keep the car TPI.

My question is about the cylinder heads. Right now the heads on the 350 are swirl port, which I've heard are no good. So I have a few options in order to get some nice heads with 1.6 rockers, which I'd love to do to complement my new cam.

#1: Can I use my 305's stock heads(#14101081) on my 350 for added compression or is there a problem with doing that?(I'll run a search on the boards too)
#2: My friend is selling some heads-casting number#3884520. These are apparently from 60-67 sbc and are 60cc chambers. These would be great except I've heard I'd need to install hardened valve seats because of the unldead gasoline now-a-days. Any opinions on this?
#3: I could buy some heads online or get some newer used ones.

Any and all opinions would be helpful! Thanks!

 

I would think the 305 heads would not flow enough air, may be too restrictive.

 

Option one is fine, you may need premium gas. Option 2 creates other issues, namely the heads don't have the holes on the ends, so you would have problems mounting the brackets for your alternator, et cetera. Option 3 is not very specific, but going to Vortec heads, along with a matching TPI base from scoggin-dickey, will get you more hp and TQ than option one, even if option one gets combined with some good porting.

 

ah i see! Well it seems like a set of new heads will be best considering my cam(CompCams 268XFI) has .570" lift if I remember correctly. It seems that the stock 305 heads won't flow well enough for that lift. So I guess i'm now in the market for some heads.

You mentioned vortec, I'll do some research on those, but do you have any recommendations? Also, if anyone else has any head recommendations like trick flow or others, throw me some part numbers and I'll price them out. Thanks again!

 

Check these out.....
Cast Iron Vortec Cylinder Head Assembly

MSRP
$407.14


Enlarge image [+]
12558060
Cast Iron Vortec Cylinder Head Assembly
Completely assembled with 1.94/1.50 valves
Uses bare head 12529093
64cc combustion chamber
Straight spark plugs
No heat risers
Requires Vortec specific intake manifold
Camshafts with more than 0.475 lift require machining
valve guide bosses and checking valve seal to valve spring retainer clearance
Can be machined for 2.02/1.60 valves
Rocker arm studs can be pinned or drilled and tapped to 3/8
Valve spring seat diameter is 1.28
Casting number 10239906 or 12558062

This head is assembled with the following components:
10241743 Intake Valves
10241744 Valve Spring Retainer
12550909 Exhaust Valves
10212810 Intake Seals
10212811 Valve Springs
12564852 Exhaust Seals
24503856 Valve Locks