Wes Hardin

What would be the best flowing gm heads I could put on my 5.3 twin turbo

justinkp

Lots of people are using the 317 heads because they're good for boost.. I'm sure there are betters though. I have 317's on a single turbo and make great power with a cheap turbo. What heads do you currently have?

Wes Hardin

I have 862 now

stock48

iTrader: (17)

I would go with 799 or 243's. 317's will lower compression too far.

CameronVic

iTrader: (5)

862s, 5.3, on 18psi.

FAST LS1

iTrader: (2)

I chose the 799's.

LILHEMI

862 heads on a bone stock 5.3, 15 psi on pump gas.

TDMKR496

iTrader: (3)

It would be nice to do some dyno testing to see what works best.

Forcefed86

iTrader: (4)

What year 5.3? OEM internals? How much power do you want to make?

IMO For most street/strip setups changing out the heads isn't worth $ per HP gained.

TDMKR496

iTrader: (3)

Do you have a build thread for your Crown Vic? That looks cool as hell!!

Wes Hardin

It is a 02 all stock. I will be putting a cam and head studs in it

Wes Hardin

I want to make 1000 rwh

Forcefed86

iTrader: (4)

Don't we all... Won't happen on 02 with OEM rotating assy though IMO.

You can make enough power with that setup on the 862 heads to bend the gen3 rods. (or so they say)

I haven’t seen any direct NA comparisons of an 862 to a 243 head with no other changes. Can’t imagine it’s more than 10-15whp? (that’s a guess) Would be great information to have. People are paying more for a set of untouched 243’s than I paid for my whole motor!

CameronVic

iTrader: (5)

https://ls1tech.com/forums/forced-in...-96-139-a.html

Ain't that the truth. I'll just turn my boost up if I wanna bend some rods!

yonerhottlt1

iTrader: (21)

I would go with 799/243 heads if it were my build...good luck either way!

Hulkls1

iTrader: (2)

I have 706 heads on my 5.3 turbo car now would it make a big diff if I switched to 799 heads?

CameronVic

iTrader: (5)

Make a difference? Yea. Big one? Not in my opinion. It'll lower compression, but flow somewhat better. Turbo cars don't react as much to heads as much as an NA or nitrous motor would. I just can't justify $400 when I could turn the boost up a couple psi if I wanted to blow my motor.

LILHEMI

You want good heads? Buy the trick flow 220 as cast. But only after you forge the motor. The chances of you making even 700rwhp on a stock motor is slim so just go with what you got.

Twin turbo c5

I like the 243's . I've run them many times. 317's work good if you want the compression to drop .

RonA

iTrader: (1)

What about the ls3/lsa heads? They seem to be quite reasonably priced and flow well.