5.3 with ls7 heads and 70mm turbo work?

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Oct 8, 2014 | 09:02 PM

Nympho

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5.3 with ls7 heads and 70mm turbo work?

I am on a budget so if I can get some oem ls7 heads what are the pros and cons ?

Current build idea

Iron 5.3 wouldnt that be stronger?
ls7 heads
z06 cam
ls6 intake magnifold
60 pound injectors
tial bov and wastegate
70mm turbo .96ar 6ish psi

through a b&m built for 700hp 4l80e
3000 stall

to a 12 bolt with 3.73 gears

profit at:
low to mid 4xx at the wheels

Oct 8, 2014 | 09:06 PM

Project GatTagO

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From: Little Austin

Quote:

Originally Posted by Nympho

I am on a budget so if I can get some oem ls7 heads what are the pros and cons ?

The biggest con being that they won't fit...

Andrew

Oct 8, 2014 | 09:13 PM

Nympho

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I read somewhere they would....okay so probably cheapest way for me to go would be ls1 heads?

Oct 8, 2014 | 09:20 PM

redtan

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LS7 heads are usually well over 1000, so if that's in your budget then so would a bunch of other nice heads. You can get some nice used AFRs or ported 243s for that same price.

Oct 8, 2014 | 09:28 PM

Nympho

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ls7 heads were on ebay for $500 last night

Oct 8, 2014 | 09:28 PM

krazy4

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Cheapest way is to run whatever heads come on the 5.3 you have.
You only want to make 450whp, that's nothing on this motor.

Oct 8, 2014 | 09:40 PM

Nympho

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450 for daily driving, I want to be able to turn it up to say 14 psi and make around mid 5xx if that's possible

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Oct 8, 2014 | 10:08 PM

Nympho

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Well I guess if I was gonna put the money from the heads into something it would better to get a precision turbo.

How much slower would a
76mm .82 A/R spool to like a MP 70mm .96ar

Last edited by Nympho; Oct 8, 2014 at 11:41 PM.

Oct 9, 2014 | 06:03 AM

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redtan

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Quote:

ls7 heads were on ebay for $500 last night

Yeah either those weren't really LS7 heads or they were heavily damaged or that was just the starting price for the bidding and not the actual purchase price. Like I said, these are worth well over 1g in good condition, so if anything you might as well buy those if they were really only $500 and sell them back on here and easily double your money.

Either way, for $450 your best bet is a set of 317s/243s. Those will easily outflow any LS1 or 5.3 head and fall within your budget. The others will work also for your goals, but why not get the best head possible for your budget?

Oct 9, 2014 | 08:07 AM

#11

ken6881

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Quote:

Originally Posted by Nympho

Well I guess if I was gonna put the money from the heads into something it would better to get a precision turbo.

How much slower would a
76mm .82 A/R spool to like a MP 70mm .96ar

I would get something in the s400 borg warner turbo series. Lots of value there and are durable. Talk to forced inductions they build some nice stuff and can recommend something for your goals and setup

Oct 9, 2014 | 10:00 AM

#12

1CAMWNDR

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LS7 heads require a 4.00+ bore. The 5.3 and 5.7 have a smaller bore. They simply will not work. They MIGHT not even fit a 4.00 bore 6.0 block.....I am not sure. They may require the 4.125 bore of the LS7.
Use stock heads with a decent valve job. More than enough to get you to 500+ hp.

Oct 9, 2014 | 10:37 AM

#13

chiaj144

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Quote:

Originally Posted by Nympho

Well I guess if I was gonna put the money from the heads into something it would better to get a precision turbo.

How much slower would a
76mm .82 A/R spool to like a MP 70mm .96ar

I've ran both back to back and didn't notice any difference.

Oct 9, 2014 | 10:39 AM

#14

denmah

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why not just run the stock 5.3 heads.
what is your hp goal

76mm means nearly nothing its only one of at least 4 important numbers on a turbo when you are sizing up what kind of power you want to make.

Oct 9, 2014 | 10:41 AM

#15

denmah

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Quote:

Originally Posted by Nympho

450 for daily driving, I want to be able to turn it up to say 14 psi and make around mid 5xx if that's possible

only 400-500whp?

gt45 68mm if you can fit it
on3 76/65 very fast spool
on3 7875 little slower spool but capable of more power

all are under 450 dollars

use the stock heads, a mild turbo cam, pac1218 springs and youll be nailing it down without issue, without blowing tons of money on ls7 hardware

Oct 9, 2014 | 09:07 PM

#16

Nympho

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After talking to a few people I'm gonna go with around a $1000ish turbo instead of like an on3.
Thinking maybe either
S400SX-62 ETR-HO 71mm .90ar
or
PRECISION TURBO 7075H (T4 .96 A/R)

with the current idea
Iron block 5.3 take out
317 cast heads
ls6 intake
and i have no clue what would be a mild turbo cam I'm guessing something like a
comp cam XR265HR

what are the thoughts on rebuilding say a $700 4l80e with the 4L80E SS MEGA MONSTER TRANSMISSION COMPLETE REBUILD KIT and a shift kit
or
buy the b&m built 4l80e

Oct 9, 2014 | 09:17 PM

#17

F110Mech

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For your goals? Stock 4L80e and a shift kit... and a stock cam... and stock heads...

you could really just stick a turbo on it with a fuel system and hit those goals

Oct 9, 2014 | 09:22 PM

#18

Nympho

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As everyone says your going to want more, I'm starting out with a want for a decent amount of power and later on down the road may want more.

Oct 10, 2014 | 09:35 AM

#19

2muchboostNY

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Like Denmah says...for your goals keep the stock heads. You can spend the money elsewhere. ****, bone stock 5.3's are in the mid to upper 600s without breaking a sweat. The whole 317 heads on a 5.3 controversy is still in the air...."its a dog out the box with 317s".

As far as the cam....ideally a custom cam is killer but even some of the other OEM cams like the LS6 or even LS9...there are others.