fastraiderX

hi im new here a friend is selling me a 6.0 truck motor for my 80 Malibu it has cathedral heads his has square port heads. which one would be better to run street and strip car want to put the biggest cam in it and run a carb also running pump gas and sum times put race fuel any tips thx ralph

EastTnZ28

iTrader: (20)

Sounds like you have alot to figure out. Id suggest you start out searching. You said his has square port heads. Heads on what? As for a cam. You need to know weight, desired rpm, kind of driving, rear gear, auto or manual, compression, etc.

ZONES89RS

iTrader: (25)

https://ls1tech.com/forums/carburete...need-know.html

Doug G

Depends on how much work you want to put into it, both heads types will work great....depending on a few factors, one may work better for you than the other.
Race gas doesn't mean you'll go faster with the same combo just by using C116 or ??? (unless it's built for it at say 12:1 or higher compression which isn't going to like pump ****)
Higher octane fuel burns at a SLOWER rate to resist detonation.

dogsballs

got a lot of scope with that engine. dave mizell ran 9.87 in a notch, i ran 10.0 with a 236/246, 613/613, 110 cam

fastraiderX

at dogsballs did you do any work to the motor im just gonna do the bottom end with arp bolts and the top also n maybe have sum porting done would like to run the biggest cam on pump gas

fastraiderX

im new to this ls motors anybody has any ideas that what i should do without goin crazy like to keep it street able but still run it once awhile to race it

fastraiderX

its a 2003 6.0 lq4 317 thats what my friend gave me its out a hd pickup my goals is to drive it on the street and once in a while race it also run nos a 150-200 shot also have a turbo 400 and the rear 3.70-4.11s

speedtigger

iTrader: (16)

I feel like I have a pretty good formula for what you are doing. You just have to decide whether you are going to stay with the 317 casting heads or go Square port. Cathedral port heads will allow for a little more piston-to-valve clearance allowing you to run a slightly larger camshaft. But, I think you will find that the square ports with a smaller camshaft will run at least a couple tenths quicker than unported cathedral port heads even if the cam is slightly smaller.

When I was faced with that question, I chose to go with some CNC ported LS6 heads from Texas Speed. The smaller combustion chambers boosted my compression and they flowed over 300 CFM all for about $1200. Then I sold my 317 heads for a couple hundo and recouped some of the expense. If you can get some square port heads for free or for cheap, you could go that way with it and still have a great combo for what you are after. Certainly enough to maybe sneak into the 10 on motor in a malibu and 9s on a 200 shot.

The next consideration is how much nitrous you want to spray. If you want to run a 200 shot, you will need a tighter converter than will be optimal without nitrous. I had a Circle D 245 MM 2b (3000) stall converter and it loved nitrous. I went to a Circle D 245 MM 4c (4000) stall converter and the car was a full 2 tenths quicker on the motor but it does not handle very much nitrous. I am going to send my converter back to Circle D and give their 245 MM 2C set up a try (about 3200-3400). Chris feels like this will be good for a 200 shot in my car.

Which way are you leaning on the heads?

Doug G

Personally, I think LS3 heads are too high (buying used). By the time you get springs and any thing else done, you could buy them new
When I was looking $650 used was pretty normal. I bought brand new with .650 springs delivered for about $1000

Route I went----> https://sdparts.com/details/gm-facto...parts/12629063
and you can get better springs, or ported, or shaved, or ???? for a few $$ more

https://sdparts.com/details/chevrole...mance/88958758

fastraiderX

hi i forgot that the trans also has a transbrake i looked at the heads on the web site they r pretty pricey ive tryin to sell my big block to get the cash to buy everything i need thx for the info

fast89stang

iTrader: (2)

They can run....just look in sig.

dogsballs

Any rectangle head ie l92, will work. Ls3 just has the nicer hollow valves. Stock head will go as good as most ported cathedral

fastraiderX

hi whats a sig @fast89stang n at dogballs so should i stay with the cathedral heads n have them ported have a friend that would do them for me or go with the ls3 heads

dogsballs

It is personal preference. Both will work. Can make 500+hp with rectangle port untouched with decent cam. Thats what i have

fastraiderX

k cool how big is ur cam ive been looking at sum like in the 540-550 lift would like to make more than 500hp if i can on 93 octane n sum times use race fuel n later add nos

fast89stang

iTrader: (2)

sig is below my post. My car has been 6.28 with 1.30 60 ft. It is cam only 6.0 with l92(ls3) heads. But both can run good.

dogsballs

Old cam was hydraulic 236/246 615/615 110. Lift in 550s is pretty tame and these motors can actually take a bit, especially with tad more comp

Petey-Pop-383

SBE LQ4, LS3's out of the box with springs.
228duration .615lift cam, 1.80 glide, 4.10's
vic jr, 950hp carb, 1 3/4 headers, 3inch exhaust.
3405lbs.
250 shot.
9.41@142.7mph
1.34 60foot

speedtigger

iTrader: (16)

How many times have you hit that thing with a 93 jet?