85LSXTRUCK

iTrader: (2)

Would a stock set of LS7 heads be better than stock LS3? If so how so?

Smokey B

Ls7's if they fit.. Better valve angle with raised runners, also smaller intake port at the face...

Smokey B

Added that a lot of BS is involed with heads as most list runner CC, which does not say or tell you anything but how much volume a runner has. Ls7 Mamo heads are 265 cc so are Mast 265 small bore heads and TSP 265 cnc program. All have the same CC runner, yet a different CSA numbers i'm willlng to bet for port size.. Always ask for the CSA not runner CC.

tech@WS6store

iTrader: (2)

For most applications and budgets and build use, the ls3 style will work great for 90% of the builds out there.

JakeFusion

iTrader: (7)

LS7 is going to make more power. The raised runner, valve spacing, and combustion chamber design all are better with the LS7.

Now, the aftermarket LS3 stuff rolls the valve over, giving you some of the benefits of the raised runner design and the chamber design. The ones that also run LS7 rockers give you the valve spacing as well.

I think the difference between aftermarket LS3 and LS7 stuff is probably 20HP.

GM LS3 to LS7 is a bit more.

But ported GM LS3 heads can do 700rwhp to the tire on a bigger motor with enough cam and E85. I've seen 454s do 700rwhp with AI LS3 heads. Would an LS7 do more? Sure. But if you don't have LS7 heads already, the cost of running aftermarket castings or procuring decent stock castings, fixing them, and porting them is nearly double what ported LS3 castings will run you.

Che70velle

iTrader: (6)

Smokey B

I understand what your saying... Main question is why when cc does nothing but give you the volume. The reason is obvious (there are porters and manufacturers who list CSA and CC numbers), as I know darn well your heads and Mast 265's don't have the same csa. This works with any head, cc may work with the same style head with valves of the same size.Typical most ls7 heads that flow over 400 have a min. CSA of 3.0 or greater * stock Ls3's are around what 3.2, stock Ls7s come in at about 2.8. You can never have to much information

KCS

iTrader: (20)

Smokey B

Cool...remember reading 1 or 2 places listing Ls3 heads as 3.2 might be cnc'ed.

KCS

iTrader: (20)

big hammer

big hammer

Smokey B

Depend on how and Who set the heads up Hammer.....Skipping factory Ls7 valve train - rockers.

Ls7 heads are the Real hot rod racer heads, ls3's are the cast aways for normal everyday use. Decent head for what it is and cost.. Figure your Mast heads are 15 degrees... Funny. You just have a Low laying ls3 port with a better valve angle? Not hating just facts.

Smokey B

Runner placement means Nothing on a Wedge head.

KCS

iTrader: (20)

Che70velle

iTrader: (6)

Smokey B

Was a smart remark......not to be taken seriously wink, wink

big hammer

tech@WS6store

iTrader: (2)

Im with Hammer the ls3 is the real hotrodders head.
Its too easily universal to not be considered that. EASILY more budget friendly.
It would work on nearly any 4.000 bore platform and up and makes great power as is with no tootsie rolls involved even. Add in some port work or other magic and they are hard to beat.
That is the name of the game since the 50s.

Smokey B

There are a lot of Ls3 blocks or bored over 6.0's that can take a Ls7 head...Most just don't know. You guys are right with the Ls3 heads and the production numbers don't lie.