408ci build, expectations/suggestion.......
04-16-2012, 01:31 PM
#21
with that combo and an M6, i would be more worried about the 12bolt. if you didnt already buy it i would consider a 9" over the 12 bolt. the 6 speeds in cammed LS1's are known for breaking 12 bolts. i would not want one behind a head and cammed 408 going through a 6 speed. but that is just my opinion.
04-19-2012, 12:25 AM
#22
On The Tree
iTrader: (2)
Join Date: Jul 2004
Location: Chicago
Posts: 102
Likes: 0
Received 0 Likes
on
0 Posts
I'm doing a similar conversion going from a 370 to a 408. I have the tfs 215, but wonder is that the best head for a 408. I also have the Fast 102, etc and 1 17/8 headers. What are your opinions on these heads.
04-19-2012, 10:16 AM
#23
with that combo and an M6, i would be more worried about the 12bolt. if you didnt already buy it i would consider a 9" over the 12 bolt. the 6 speeds in cammed LS1's are known for breaking 12 bolts. i would not want one behind a head and cammed 408 going through a 6 speed. but that is just my opinion.
Not saying th 9inch isnt better, because it is by a long shot, but my moser is doing fine!!! lol 
04-21-2012, 06:07 PM
#28
Teching In
Join Date: Apr 2012
Location: Kearney, Nebraska
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
The only other question that I have is wat type of spark plugs to use of should say how hot to use. I'll post the dyno sheet on this thread to show what it makes! Thank you again
05-17-2012, 06:31 PM
#30
10 Second Club
Thread Starter
iTrader: (6)
Join Date: Aug 2006
Location: Kearney, NE
Posts: 643
Likes: 0
Received 0 Likes
on
0 Posts
Dyno Results are in.....
Tuned By DynoSport in Lincoln, (Im just reviewing the logs)
Any suggestions:
(23* on best pull, 444whp was with 28* Timing)
Tuned By DynoSport in Lincoln, (Im just reviewing the logs)
Any suggestions:
(23* on best pull, 444whp was with 28* Timing)
05-17-2012, 10:06 PM
#39
10 Second Club
Thread Starter
iTrader: (6)
Join Date: Aug 2006
Location: Kearney, NE
Posts: 643
Likes: 0
Received 0 Likes
on
0 Posts
My Personal H/C/I Z06 is at 92-95KPA, Friends FAST 102, 100mm MAF, FTP 104 Lid, PRC 227 heads, VX.4 Cam LS1 is at 92-94KPA. When my GTO was Magnuson blower only it was 98 to 100KPA!
05-17-2012, 11:05 PM
#40
Well I was under the impression that it should read 100kpa (no vacuum). I always thought that if you were creating a vacuum of any kind at WOT, it meant your plenum area was not filling fast enough to keep up with the engine demand. I could be wrong though.