408's plz come in
03-07-2010, 03:38 PM
#1
408's plz come in so my ls1 motor is completely finished. time for a 408. really dont know to much bout l92s or anything like that so i need some help. id like to get in the 550-575 hp range if thats possible. sorta on a budget since this is unexpected. id like a pretty radical cam. and i dont no what heads to get? also i mite be spraying a 150-250 shot in the future. i have 1 3/4 headers and a ls6 intake on my current motor. i dont know how restrictive those are gonna be for my goal. so please post up some ideas and some numbers of what you guys have!
03-07-2010, 03:49 PM
#2
I wouldn't spray a 250 shot on L92's too many times, deck is kinda thin and has been an issue for big boost and spray. Carey's makes a nice L92 head but if you're on a budget they might be a bit much $$$ but certainly worth a look.
iron 408 is a great bottom end for a big hit/boost and can be found relatively cheap.
You can get a good set of heads from Cartek, that's who I always use and they can spec you out a cam just right for your combo.
iron 408 is a great bottom end for a big hit/boost and can be found relatively cheap.
You can get a good set of heads from Cartek, that's who I always use and they can spec you out a cam just right for your combo.
03-08-2010, 11:24 AM
#7
Buy my race engine, and if the race fuel is a concern, I'll pay to have it freshened up if you want to buy a set of pump gas compression pistons to put in it... stick and a 10 bolt even with the compression dropped you'll be in teh power range you're looking for I'd think.
single 65 jet on a conservative tune puts a 3350 lb car to 9.50 all day long, and with a little timing in it the car went 10.50 @ 3600 lbs all day as well...
Might be a way to get a really good piece without spending a fortune.
single 65 jet on a conservative tune puts a 3350 lb car to 9.50 all day long, and with a little timing in it the car went 10.50 @ 3600 lbs all day as well...
Might be a way to get a really good piece without spending a fortune.
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03-08-2010, 11:55 AM
#8
so my ls1 motor is completely finished. time for a 408. really dont know to much bout l92s or anything like that so i need some help. id like to get in the 550-575 hp range if thats possible. sorta on a budget since this is unexpected. id like a pretty radical cam. and i dont no what heads to get? also i mite be spraying a 150-250 shot in the future. i have 1 3/4 headers and a ls6 intake on my current motor. i dont know how restrictive those are gonna be for my goal. so please post up some ideas and some numbers of what you guys have!
03-08-2010, 04:55 PM
#10
I thought GM High Tech Performance Magazine had an article on a 408 build in the August and September 2008 or 2009 issues of the magazine.
From what was in that article, the build had upwards of 550 hp with CNC L92 heads and fuel injected. That might be a future build idea to start on, at least for myself.
500-550 hp should not be a problem with the LQ9 408 stroker.
From what was in that article, the build had upwards of 550 hp with CNC L92 heads and fuel injected. That might be a future build idea to start on, at least for myself.
500-550 hp should not be a problem with the LQ9 408 stroker.
03-08-2010, 06:23 PM
#12
i was planning on selling my ls6 intake and get either a fast 90 or 92 then swap my pacesetters for texas speed 1 7/8. for a cam i was thinking a 253 257 .646 .635 112. a guy near me has this in his 408 and making rly good power. now im jus stuck on heads i have no idea what heads to get. and for fueling would 42#ers and a racetronix fuel pump be fine?
03-08-2010, 07:01 PM
#13
's, it was indeed a great thread...still waiting on those secret cam specs though, as I am doing a 408 with L92's as well as a 427 with L92's...
Wanting to get the most from it without all the drama associated with big cams and efi.
03-08-2010, 10:47 PM
#14
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Check out the Texas Speed and Performance website for heads. The PRC 237's would work great on a 408. Those and a healthy cam should easily get you in the 550 range (with supporting mods). 42# injectors "should" be enough, depending on how wild you get with the spray later, but you are definitely going to want a good pump to supply them.
03-13-2010, 03:28 PM
#17
im stuck with deciding if i want to go with 243 heads or ls3 heads. i was thinking either one of those plus a fast 90, 1 7/8 headers and the cam listed above. or maybe an ms4. what do you guys think that setup would make? and what heads should i go with with that big of a cam?
03-14-2010, 02:10 PM
#18
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253 257 .646 .635 112
With that cam, you are going to want (and need) better flowing heads than either set of stockers. The L92's may limit your lift, depending on the pistons used. If you are looking at a cam that big, spend the money on an aftermarket set of heads, and you will kill your HP goal.
As mentioned above though, pick the heads that you are going to use, and then have someone spec you a cam to match. You're going to be pissed if you get it all together, and get outrun by a cam-only car because you picked a poor combination of parts.
BTW, you can't get a FAST 90 for L92 heads.
With that cam, you are going to want (and need) better flowing heads than either set of stockers. The L92's may limit your lift, depending on the pistons used. If you are looking at a cam that big, spend the money on an aftermarket set of heads, and you will kill your HP goal.
As mentioned above though, pick the heads that you are going to use, and then have someone spec you a cam to match. You're going to be pissed if you get it all together, and get outrun by a cam-only car because you picked a poor combination of parts.
BTW, you can't get a FAST 90 for L92 heads.
03-14-2010, 03:58 PM
#20
if i can get a good deal on a shortblock i can probbably get a set of used trickflows but mite need to hold off on the fast unless i can get a good deal on that to. so you think with that cam and either some worked 243s or trickflows il surpass my goal? what would it run in the 1/4 around? and would it be a dog down low?