I am looking for a cheap head replacement for my LO3 engine. I want it to be as cheap as possible while actually gaining some performance. Any brands to look for? Will some junkyard vortec heads work well? I am switching over to carb if that will help any.

 

Watch which Vortecs you get out of a junk yard ..... there are two different kinds ( different casteing #'s) the one is a good one and the other is useless.

do a search you might find this ..........I forgot where I got the info ....but I will post a link if I can remember it

good luck vortecs are the best bang for the buck I am told

 

With Vortecs you will need a $200 intake.

 

The cheapest performance head swap for a 350 TBI is to get a set of HO or TPI 305 heads rebuilt and upgraded with
performance springs and new larger 1.94 valves along with some
porting. Find a serviceable set, get a die grinder, port them up
yourself and take them into a automotive machine shop for
a rebuild and upgrade. ( springs, pinned studs, bigger valves,
3 angle valve job, New guide linners if nessessary.) You can also have them shaved a bit to raise compression a bit. Do not exeed 10:1 for street gas.

The 305 head castings to look for are 416 or 450 for the older pre 86 style HO heads and 081 for the 87+ 305TPI heads.

Both these heads have 58cc chambers. When you sweep out the chambers to fit the larger valves you'll be at 60/61cc's.
Just have them shaved a bit to return to 58cc.
These heads come alive with the porting and larger valves.

Once this is done your motor will be wanting a little bigger cam
to go with the improved head flow.
How big to go will depend on the rest of your planned mods.
A better exhaust system will help a lot.

You can expect some 30+ horsepower gain.

 

could I just use my stock 305 heads and rebuild/port them?

 

zero,

The LO3 305 uses "swirl-port" head castings and they are too much trouble to straighten out. Do as F-Bird'88 says--he's about the smartest head porter on the site. Follow my instructions linked at the end of my sig.

Good luck

And if you need any help, contact either me or F-Bird'88