ckpitt55

iTrader: (4)

I am in the middle of an LS1 build, the block is ready to be sent to the machine shop for deck plate honing, main journal align honing, and balancing of the rotating assembly. It's going to end up as a 347, with 11:1 / 8.5:1 (SCR/DCR) numbers in mind.

After I got quotes for the head work required to bring the 241's up to where I want them to be (~$250 for a valve job, ~$300 for a 0.020" mill (more $$ for extra milling, and all the associated replacement seals etc.), I got to looking at aftermarket heads. For the same total price for what it'd take to get the 241' worked and assembled or less, I could end up with something that's going to flow much better than worked 241's would.

I was considering something like the PRC Stage 1.0 ported LS6's, but noticed most of their gains in flow over the 241's come in the upper to mid lift region. From what I've read low lift flow seems to be important for torque - I'm looking to build a motor for area under the curve. I don't care about peak hp so much as I do grunt from a dig, as it's going to be primarily a street car and my DD. Can anyone give me some pointers on head selection, given my budget and goals?

Thanks for your time,

poltergeist 02

iTrader: (65)

you could always just use stock 799 or 243 heads.

lemons12

iTrader: (71)

I have the heads from my 346 setup if you are interested. They perform awesome and are budget friendly.

A 5.3 2.5 head would be a much better choice for what you want if you are looking at a prc ls6 head. They make way better low and mid range power.

senicalj4579

iTrader: (41)

I would just do the prc 5.3 heads. Great deal and it will get you what you want. If not then I would call mike at tea and have those 241s done.

ckpitt55

iTrader: (4)

thanks guys, I'll check into the 5.3 heads. seems as though they'll give me every bit of the compression I want without milling which is a plus.

what heads were you running on your 346?

HCI2000SS

iTrader: (2)

I'm really happy with the 5.3 heads. Awesome midrange power IMO

lemons12

iTrader: (71)

Set of 317s. They were milled thirty and ported... I ran 7.2-7.3s @ 95+ in 2200+DA with a nitrous tune in the car. 3500# 226 cam, stock ls6 intake, 1 3/4 headers ory and magnaflow, etc.. The heads do work.

low2001gmc

iTrader: (148)

243s will be best for now and down the road (porting). stock will work great up to 600 lift. of course ported down the road even better. good luck with your project

ckpitt55

iTrader: (4)

just found this thread, seems to be pretty relevant haha

ported 243's or stage 2.5 5.3 heads

I'm considering a 228 cam - is it just me or is there a lot more area under the curve with the 5.3 heads from 3k to 4.5k, disregarding peak numbers (both cars used the 228R).

edit: maybe it's just the scaling that's throwing me off, numbers seem to be pretty consistent, with the ls6 peak coming later in the rpm band

2.5 LS6's:



2.5 5.3's:

andy9743

i called tsp for the same type of situation they recommended that i go with the 2.5's over the 1.0 heads...i'm building a DD type car also.