View Full Version : 418 LS3...243, TFS, or LS3 heads????

04-17-2009, 07:49 AM
Working on a budget here so please give this some significant thought...

07' TBSS AWD, previously with AI CNC 243's, 226/230 cam, vig 3200 stall and the usual bolt-ons, 4800lb, -300DA, ran 12.18 @ 109-110...Shortblock spun a rod, so must rebuild. I'm thinking of 418 LS3 or 440 LS7, I'd definitely go LS7 if I had the $$, but we have other expenses right now. Based on my calculations I believe I need to make 620-650hp at the crank...we would like to trap "close" to 120mph in 0 DA weather...My concern with my plan is am I going to make enough power with a cathedral port aftermarket head or CNC LS3 head to warrant the added expense over just re-using my 243's for now?

If I go with TFS (NOT fast as cast) or WCCH edlebrock heads I'm talking $2500, + rockers, + intake, + fuel rails, + maybe a fabbed fuel line, then depending upon which intake I may have to modify the front accessory drive. So I'm out probaby $3500 minimum.

If I go with CNC LS3 heads then I'm talking $1900, intake rockers, pedistals, intake which would either be the FAST LSXR (BEST option, but may not be out soon enough) or L92 truck intake (more cost effective, be obviously not the big power maker), along with fuel rails etc, and possibly an accessory drive change. So I'm out probably $2500-$3300 depending upon which intake is chosen.

Option 3 is reuse my heads on the 418 LS3, which wouldn't cost me anything.

Option 4 is bite the bullet and go LS7 440, then use some stock LS7 heads/intake. I haven't looking into this option much so I really am unsure about pricing.

Which option will get me closest to my goal of 620 - 650hp fly wheel for the least $$...I'm also considering the TFS/WCCH Edlebrock option and re-using my stock TBSS intake for now, then switch the intake out later when $$ are available...Then I'd just be out pretty much for the heads/rockers for now....

Please throw in your thoughts....

04-18-2009, 08:20 PM
If I was on a strict budget like you, I would just use my LS6 Heads and when I had some more money I would do the LS3 Head combo.

04-22-2009, 02:12 PM
dont go for max power you have a very heavy suv so build some thing with good power from 3000 to your shift point. id stay TF heads they will get you little more TQ over all which you need to get that moving. If you want build the 440 stay with your heads for now at later time move to TF 235 or TF245

High revs and high hp is Great for track only cars and very light cars

Jason 98 TA
04-27-2009, 12:25 PM
Don't rule out the PRC 237cc LS cylinder heads. We recently had several LS3's on the engine dyno making 670-700 flywheel horsepower with those heads & high 240 duration camshafts!

04-27-2009, 07:07 PM
I keep forgetting about the PRC 237 very nice head too. You Guys have to list all the spec of this head again. I think it has a very nice thick deck like .700 or some thing