408 Build , what top end??

[Sebambam]

Hey Guys
im planing in a 408 , 410 or 416 build

i have a LQ4 sitting here that i will bore over
and i will get a SUMMIT PRO LS KIT to stroke it.

can a Iron block take the .070 Overbore for a 416?
I am running it NA

What GM top end kit would you do

catherdral port 799s/243s
or
Rec Port 823s

i have clearance for a TBSS Intake

[71CUTTYS]

I was planning on doing .065 over on my 6.0 block. Machine shop said most can go that far but they will need to check first. As far as top end, the square ports flow significantly better than cathedrals but it tends to move the power higher up in the RPM band. I am doing cathedrals on my 408 due to the combustion chamber sizes available in cathedrals will make it easier for me to achieve the compression i want. Any head you should should be aftermarket IMHO - I got my eyes on TFS 225s.

[KEGS73]

Im doing a cathedral port top end using a ported set of GM 243 heads, 60lb injectors,103mm FAST intake and throttle body. Compression will be at 11.3:1 on my set up.This is all going on top of a 416ci LS3 block. Similar combos to mine are in the 500-550 range at the wheels. Don't get to hung up on the cubic inches. Unless you are going for max output racing those numbers are too close to make a huge difference. work with what ya have and keep that cylinder wall thickness at a safe thickness. no sense in dropping a crap load of money into it just to crack the cylinder wall down the road. There is no single great combo. Theres a lot on this platform to choose from. All boils down to your budget and goals really

[slazisme]

1. https://www.airflowresearch.com/260cc-ls3-cylinder-head/p582
Price not an issue.....these.

2. https://www.summitracing.com/parts/nal-12675872/make/chevrolet/model/camaro/year/2012
Good bang for your buck, just change springs with some PAC's.

3. https://www.airflowresearch.com/238cc-ls3-enforcer-as-cast/p612
72cc chambers, depending on pistons used compression could vary, priced well.

FAST or LS3 intake if on a budget & use heads from #2 or #3.

[Sebambam]

Very cool
So I decided to drop of my 799s to get them fully ported , milled and add bigger valves.
& btr .660 dual springs will be installed.

I have Alu LS2 fresh bottom end
And the he iron LQ 4

I can install this heads on either or , whatever I decide to use
With a nice BTR cam in the 625 range

I want to pair it with a 6 speed trans