408 question

Reply Subscribe

Thread Tools

Search this Thread

Feb 20, 2011 | 10:24 PM

ocls1

Thread Starter

Teching In

Joined: Feb 2011

Posts: 37

Likes: 0

408 question

I have a lq9 bored and stroked to a 408.......Diamond Flat top pistons with-2 cc vavle relief pistons callies rods and callies 4"crank. My budget is really tight so right now these are my options.

317 casting milled with valve job
243 with valve job
241 with valve job and some porting

I was wondering which one of these is best for my setup?
I know i can there is a better option of heads but for right now this is all my budget is letting me do.... any imput will be appreciate it!

408 is stock deck height

Feb 20, 2011 | 10:28 PM

htownws6

10 Second Club

iTrader: (1)

Joined: Dec 2009

Posts: 107

Likes: 0

probably the 243's

Feb 20, 2011 | 11:13 PM

txh0tb0i972

TECH Enthusiast

iTrader: (63)

Joined: Apr 2007

Posts: 595

Likes: 14

From: Dallas/Lancaster

IMO id say mill down a 317 have a valve job and then some slight port work done to them.
With the larger CC I personally think they will flow alot better and you can run a thiner head gasket to make up some of the compression

Feb 21, 2011 | 10:00 AM

ocls1

Thread Starter

Teching In

Joined: Feb 2011

Posts: 37

Likes: 0

so 243s or 317 castings? Not sure if ill have enough to do the port work to the 317 castings but ill find out. I might be able to get some l92 at a good price if i decide to go that route

Feb 21, 2011 | 01:40 PM

Sales4@Texas-Speed

LS1TECH & Trucks Sponsor

iTrader: (4)

Joined: Jan 2007

Posts: 1,768

Likes: 9

I think you almost have to run the 317s to keep your compression beneath 11.5:1. The 243s with a 64cc chamber will have you at 11.8:1 with that -2cc piston. You will have to run the 317s so you can stay on pump gas, you can mill them some to get added compression though. A 68cc chamber would put you in a pretty good spot with the setup you have.