317 heads vs. 243 heads???
#1
317 heads vs. 243 heads???
I am new here and am getting ready to install a 6.0 motor in my 1970 camaro. The 6.0 motor has 317 heads on it now, I am thinking of trying to find a set of 243's. Will it benefit me?? Am I gonna notice the difference?? Is the money better spent elseware?? I will be installing a LS6 intake and cam, as well as headers. Thanks in advance for advice.
#2
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,605
Likes: 0
Received 6 Likes
on
6 Posts
There's two 6.0 iron blocks (LQ4, LQ9) that differ in
the pistons and use the same 317 heads. The hotter
LQ9 I think is about 10:1 CR. If you went to 243 heads
you'd probably be over 11:1 with the LQ9. That starts
to want good gas or tuned for lower timing. If you want
a big bump in CR on a LQ4 motor without changing the
pistons, they might not be a bad idea.
LS6 cam is a waste of labor in my book. Minimal change.
the pistons and use the same 317 heads. The hotter
LQ9 I think is about 10:1 CR. If you went to 243 heads
you'd probably be over 11:1 with the LQ9. That starts
to want good gas or tuned for lower timing. If you want
a big bump in CR on a LQ4 motor without changing the
pistons, they might not be a bad idea.
LS6 cam is a waste of labor in my book. Minimal change.
#4
12 Second Club
iTrader: (2)
if your going auto spend some $$ on a good convertor these engines make good power starting around 3500 rpm so an aggressive convertor will put you right where its happy
#6
if the heads are coming off consider milling them .look at a Texas Speed cam kit.the 224r is a nice mild street cam.keep you coil packs .check out Texas Speed for the parts you mite need.
Trending Topics
#8
TECH Veteran
iTrader: (23)
I am new here and am getting ready to install a 6.0 motor in my 1970 camaro. The 6.0 motor has 317 heads on it now, I am thinking of trying to find a set of 243's. Will it benefit me?? Am I gonna notice the difference?? Is the money better spent elseware?? I will be installing a LS6 intake and cam, as well as headers. Thanks in advance for advice.
Your setup should make 400+rwhp.
#9
11 Second Club
iTrader: (2)
the 317 heads have the same runner shape as the 243s and flow nearly as
well (chamber shape difference)....The 243s will raise an LQ4 to around 10.5
and an LQ9 to like 11 to one compression. The cam to match should be in the
230-234 duration range for totally streetable pump gas friendly power........
well (chamber shape difference)....The 243s will raise an LQ4 to around 10.5
and an LQ9 to like 11 to one compression. The cam to match should be in the
230-234 duration range for totally streetable pump gas friendly power........
The following users liked this post:
perry223 (12-24-2019)
#10
TECH Enthusiast
Have you considered 821 heads? Some say they are the way to go on a 4 inch bore, and they can be had brand new for very reasonable prices, as they are current production pieces, on LS3's and the new 6.2L truck engines.