speedfreak2685

iTrader: (12)

I can get a full 5.3 motor with about 115000 miles on it for $100. Heads are off it and no accessories but all covers are there. I figured I could sell everything but the heads and come out with no money invested in the heads. They are 706 castings if I remember corectly. Would they be worth swapibg onto my 99 Camaro? I have full boltons and a ms4 cam now. Of course I would take them to a mechine shop and have them cleaned and checked before I put them on and I would need to buy new head bolts and gaskets and such so that would be a little money but not bad. I would probably lightly port them as well. Is it worth the time and little bit of money to swap them out and how much power could I gain by doing so?

PREDATOR-Z

Not ported, no.

garygnu

you can get some used 243/799 heads for $400.

speedfreak2685

iTrader: (12)

I would do some porting on them myself. Smooth out the runners and such and clean up casting marks. Im pretty sure the said 706 casting. Is that possible or were they 799 casting and I read it wrong?

supersick99z

iTrader: (66)

Ported, yes. Unported, no!

Sarg

iTrader: (6)

They also have smaller intake valves. So factor in having to get larger valves installed and machined.

speedfreak2685

iTrader: (12)

How much money do you recon I will have in machine work for the larger valves and buying the valves and valve job and such has well as cleaning up the heads? Just trying to see how much I will have in everything after its al over to see if its worth it.

Sarg

iTrader: (6)

I think it varies...I have seen anywhere from $150-$300. But then I have also been told that it is better to replace the seats at the same time when going to larger valves which can get a bit expensive. It really just depends. There are shops out there that charge half that, but I have never had anything done by them. I use the guys we trust over at MTI.

PREDATOR-Z

Even if you change the valves, a non ported 5.3L head is worthless.
You need to CNC them and change valves.

Reed35

remember, 5.3 heads also have smaller combustion chambers. so they will raise your CR slightly. If i remember correctly, the 706 head had a recall for porosity in the casting, so definately get them checked first.