Infamous

I posted this in "External Engine" but all the seasoned vets are giving me this look; . So here it is again in the newbie section.

Did a search for these answers and wasn't satisfied.

I have the oppurtunity to purchase a set of 5.3 heads from a friend who owns a cylinder head shop here in Michigan. He says they are brand new castings that he CNC ported, 58cc, 2.02/1.57 and flow 310. They have all Manley hardware in them. He says he'll sell them to me for $800. Is that a good price and are these pretty good heads? What is a 5.3 head? Also, what potential valve cover problems or any other issues do you see if I decide to run with them? I have an LS6 intake I plan to use on this motor.

Thanks. I owe you a life debt if you answer this thread.

MillaTK

you probably got those "looks" because this doesn't belong in the external engine section. You'd be better off posting in the internal section.

sdbrown84

iTrader: (22)

Yeah internal section. That seems like a price about what it would be for a set of those heads CNC'd, maybe a little high. He is making some $ off of you for $800. Especially if they are used double check everything, and make sure he includeds a set of quality springs/retainers/locks in the deal.

Infamous

Interesting. I guess I had thought "internal engine" meant crank, rods, pistons, camshaft, lifters, etc., and that the heads (being outside of that area) would be considered external. My mistake. Thanks for the heads up on the price. He's an old friend but one I haven't talked to in years.

Interestingly...another guy on another site said those heads would be a steal at $800.

jimmyblue

iTrader: (11)

5.3s will bump up your compression a lot. There are
chamber volume based CR posts in the Internal section.
You need to be somewhere that fuel quality is high, to
want the 5.3s on a 5.7 stock long block. If all you have
is 91 octane, I wouldn't.

310 is a mighty high flow number for a stock head even
ported. Couple of things. One, to get that high you may
have sacrificed things that make for decent low- to
mid-RPM torque and fuel economy (mixing from swirl).
Two, that high a number may have come from a
funny flow test, at lifts higher than a sane cam will
give you or at higher than the cam you mean to use,
will open a valve.

For the amount of work done and the parts on it,
the price seems fair. But whether these heads fit
-your- motor plan, is the right question to ask. If
not your car may be a stumbling pig on the street.

jpat1023

Good Post!

Infamous

Thanks Jimmy. That was the advice I was looking for. I too was weary of the high compression.

DJ_951

With a milder cam I wouldn't worry that much about the compression. ARE had some nice heads, 310 probably Isn't a conservitve number but most arn't. The price sounds good. The other qustion is how many miles on the springs and what cam. If unknown I would replace the springs. (still a good deal on heads????) With a 224/224 mid lift cam and supporting boltons 400rwhp is easy.

Good heads will make or break a engine. 300cfm is the magic # for a LS1 engine. In theroy you would have heads capable of 500hp with a resonable cam.

99blancoSS

iTrader: (115)

The money here is very good. most people charge 600-750 for cnc'ing alone. Then you add in the manley hardware and you can see its not a bad deal at all. But I thought I read about manley spring failures?

You can get a used set of 5.3's with used dual springs for anywhere from 600-800.

WS6 Rampage

iTrader: (3)

I'm thinking about go'n with a 5.3 heads and cam profile and wanted to ask,....CAN I still use 91 octane w/o any issues or do I need to use something else?

staringback05

iTrader: (8)

do you have FI or a bottle?....if so you might have to use some stabilizer....compression without those isnt that bad at all though