What are the best aftermarket heads that can go on an LG4? Right now my compression is 9.5 - 1 and i would like to raise that to 10.5 - 1. So what are my best options?

About the only choice for that is the Dart Iron Eagle 49cc ones.

Know that 10.5:1 will probably require premium gas - have deep pockets for that extra 20 cent a gallon hit?

10.5 is getting pretty high for even 92oct with iron heads!

So if we drop the 10.5-1 compression, what are the best heads to fit in an LG4 engine aside from the stock ones?

What do you plan on doing with the engine?

Whats the rest look like?


Is it going to be a 500hp monster that needs some AFR's or is it a mild 250hp mouse that needs something more along the lines of vortec's or even just some ported stock castings...

Well, basically all i have right now is 1 and 3/4" exhaust and a 3"y-pipe, but other than that, the engine is bone stock. I'd like to turn it into a 250-300 hp car. I havent fully decided on any parts yet, but i was looking at the edelbrock power package.

sticking with the LG4 you may as well port the stock heads. Shouldn't be a problem getting that HP #. Sitting bull and Mwnova did quite well with LG4s. However if you get a package deal like that, you can always reuse the heads on your 350 later (not if, but when...)

oh, edelbrock flat tappet cams aren't the hottest thing out there, just an FYI.

check out the lunati voodoo cams, I refered to them and I was quite impressed as to they cuts they put into these cams.. You can probably even leave the stock heads(some work maybe required to the valve boss due to lift), just up the compression via $10 Federal Mogul piston and an edelbrock intake. A new holley carb might help later on.

If at any point a camshaft upgrade is desired, I would do that in correspondance to whatever you go with as far as cylinder heads. Like aforementioned, porting out some old 416's or maybe a 601 casting (I think they had slightly smaller combustion chambers?) woud be the easiest thing. Just go junkyarding for a set and work on them and swap them out whenever. Have you looked through past threads to see what's involved with this (they're not that hard at all).

I agree on the Edel. crapshaft, err camshaft I mean.

I wouldn't worry about switching to a Holley. For a street car the q-jet is the best hands down. The intake really isn't a restriction point, either.

I picked these out awhile ago for machined 416's with some help of the drag racers...

PN: 60102LK
262/268
219/227
.468/.489
112/108
1400-5800

pn
60103LK
268/276
227/233
.489/.504
110/106
1800-6200

The voodoos are nice cams. i've got the 60103 in my 305 headed 350.... should be able to fire it up any day now, i've got high hopes.

Vortecs might be a good choice as well. You could have them milled down a bit to get the CR up. Ported 416s or 601s are a decent choice as well.

I was gonna put that in my 315.... had to wreck that ice burner...lol

yeah,, for a 305 just use gm parts and work them over... you dont need thousand dollar heads... the 305 should be right where you want it hp wise as well

or even the 081 heads are good ( TPI HEADS) . I am supprised nobody suggested the S/R torquers ?

World Torquers are very similar to stock.... AFR 180's..lol Umm, Trickflow makes 305 heads and so does another major brand but they aren;t listed u seriously have to search for them...

what is the stock LG4 head combustion chamber size?

Port the stock heads, pin the rocker studs or put in screw-in studs, new valve springs to match a fairly simple cam upgrade. You're there with 9.5:1 CR.
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58cc, with actuals in the low 60's.