Top end options for 408 stroker
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Teching In
Joined: Apr 2016
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Top end options for 408 stroker I've got a lq4 that recently locked up on me. I haven't gotten to pulling it apart yet so I don't know happened yet, but it got me thinking maybe it's time to bump up to a 408 like I've been wanting to but it's only in the budget right now if I can reuse my existing parts. The car has 5.3 heads now that have been milled .050" and ported with 2" valves installed, not sure on flow numbers. It has an ls6 intake, ported throttle body. Cam is a comp 243/251 with .624" lift on a 111 lsa. Chromoly push rods, and brian tooley valve springs. Also running a t56 and this will now being going into a 72 chevelle. My concern is the heads. Will they perform well with this setup and will it make a noticeable difference over the stock cubes? And what pistons do I need to keep the compression in check? Any thing else i should know? Thanks for the help guys
Thread Starter
Teching In
Joined: Apr 2016
Posts: 8
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I wish I could tell you more about them. They were already done when I got them and I listed everything I know about them. I don't know much about headwork myself, I will try and get in touch with the guy I got them from and see what he knows
TECH Addict
Joined: Jul 2013
Posts: 2,189
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From: Portland, Oregon
Get better heads. Those are not the heads you want on a ~400ci stroker. That cam would do better with rectangle port heads, too.
Even CNC'ed 4.8/5.3 heads have ~213cc intake runners, which is quite lacking for a 400+ inch engine. Your heads, even in the best case scenario, flow 290cfm, maybe, on a good day. That might give you 500hp at the flywheel, which is sad and boring and lame when considering you'd have a 408ci stroker that should be making ~700hp at the flywheel.
My advice, for what it's worth, would be to look into Tony Mamo's new 223cc Sportsman heads, for ~$2100. Or the Trick Flow Specialties 220cc Fast as Cast heads, for ~$2000. Both of those would allow you to reuse your LS6 intake. I would invest in either of those heads on a stock displacement six liter, even before stroking it to 408ci, but that's just me.
If you want to make some real power with a 400 cubic inch stroker, read and study SpeedTrigger's build. He is using a really proven and popular combination of LS3 heads on a stroked LQx, and is pushing over 700hp at the flywheel naturally aspirated. Legit.
Even CNC'ed 4.8/5.3 heads have ~213cc intake runners, which is quite lacking for a 400+ inch engine. Your heads, even in the best case scenario, flow 290cfm, maybe, on a good day. That might give you 500hp at the flywheel, which is sad and boring and lame when considering you'd have a 408ci stroker that should be making ~700hp at the flywheel.
My advice, for what it's worth, would be to look into Tony Mamo's new 223cc Sportsman heads, for ~$2100. Or the Trick Flow Specialties 220cc Fast as Cast heads, for ~$2000. Both of those would allow you to reuse your LS6 intake. I would invest in either of those heads on a stock displacement six liter, even before stroking it to 408ci, but that's just me.
If you want to make some real power with a 400 cubic inch stroker, read and study SpeedTrigger's build. He is using a really proven and popular combination of LS3 heads on a stroked LQx, and is pushing over 700hp at the flywheel naturally aspirated. Legit.
If you're trying to feed 408ci on a budget, I'd go with LS3 heads without hesitation. I would want a different cam though, but it would work better in the 408 than it did in the 6.0L. In a Chevelle, I wouldn't even consider a plastic OEM style manifold and go straight to a single plane manifold, like a Vic Jr, and 4150 EFI throttle body.
Get better heads. Those are not the heads you want on a ~400ci stroker. That cam would do better with rectangle port heads, too. Even CNC'ed 4.8/5.3 heads have ~213cc intake runners, which is quite lacking for a 400+ inch engine. Your heads, even in the best case scenario, flow 290cfm, maybe, on a good day. That might give you 500hp at the flywheel, which is sad and boring and lame when considering you'd have a 408ci stroker that should be making ~700hp at the flywheel. My advice, for what it's worth, would be to look into Tony Mamo's new 223cc Sportsman heads, for ~$2100. Or the Trick Flow Specialties 220cc Fast as Cast heads, for ~$2000. Both of those would allow you to reuse your LS6 intake. I would invest in either of those heads on a stock displacement six liter, even before stroking it to 408ci, but that's just me. If you want to make some real power with a 400 cubic inch stroker, read and study SpeedTrigger's build. He is using a really proven and popular combination of LS3 heads on a stroked LQx, and is pushing over 700hp at the flywheel naturally aspirated. Legit.
Another thought, if you want to consider it, would be LS7 heads and matching MSD intake. That would REALLY haul *** up top
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Launching!
Joined: Jan 2008
Posts: 275
Likes: 1
From: TX
Get better heads. Those are not the heads you want on a ~400ci stroker. That cam would do better with rectangle port heads, too.
Even CNC'ed 4.8/5.3 heads have ~213cc intake runners, which is quite lacking for a 400+ inch engine. Your heads, even in the best case scenario, flow 290cfm, maybe, on a good day. That might give you 500hp at the flywheel, which is sad and boring and lame when considering you'd have a 408ci stroker that should be making ~700hp at the flywheel.
My advice, for what it's worth, would be to look into Tony Mamo's new 223cc Sportsman heads, for ~$2100. Or the Trick Flow Specialties 220cc Fast as Cast heads, for ~$2000. Both of those would allow you to reuse your LS6 intake. I would invest in either of those heads on a stock displacement six liter, even before stroking it to 408ci, but that's just me.
If you want to make some real power with a 400 cubic inch stroker, read and study SpeedTrigger's build. He is using a really proven and popular combination of LS3 heads on a stroked LQx, and is pushing over 700hp at the flywheel naturally aspirated. Legit.
Even CNC'ed 4.8/5.3 heads have ~213cc intake runners, which is quite lacking for a 400+ inch engine. Your heads, even in the best case scenario, flow 290cfm, maybe, on a good day. That might give you 500hp at the flywheel, which is sad and boring and lame when considering you'd have a 408ci stroker that should be making ~700hp at the flywheel.
My advice, for what it's worth, would be to look into Tony Mamo's new 223cc Sportsman heads, for ~$2100. Or the Trick Flow Specialties 220cc Fast as Cast heads, for ~$2000. Both of those would allow you to reuse your LS6 intake. I would invest in either of those heads on a stock displacement six liter, even before stroking it to 408ci, but that's just me.
If you want to make some real power with a 400 cubic inch stroker, read and study SpeedTrigger's build. He is using a really proven and popular combination of LS3 heads on a stroked LQx, and is pushing over 700hp at the flywheel naturally aspirated. Legit.
Launching!
Joined: Jan 2008
Posts: 275
Likes: 1
From: TX
Last edited by TX98Z28; Apr 21, 2016 at 03:29 PM.
Thread Starter
Teching In
Joined: Apr 2016
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I appreciate all the reply guys! Finally got the heads off today and what do ya know I'm missing a rod and piston on the #8 cylinder that are now floating around in the oil pan somewhere. I previously found a broken timing chain and had already replaced thinking that was it. Found the missing piston when I pulled the head to replace one bent valve thinking that would have her back on the road in no time lol boy was i wrong. But what I did forget to mention was that I'm only 17 and have already spent 20+ grand on (and no not my daddys money) the chevelle full frame off, so I don't have the money to buy new heads/intake on top of the cost for the new shortblock. Can anyone give me any budget friendly recommendations that can get me going for now? Really just trying to get the chevelle on the road it's been a project for almost 3 years now. Could i use my heads/cam/intake on it for now and still make decent power? As far as the plastic intake in the chevelle i planned to eventually switching to the holley intake.Thanks again guys. Also should mention that I hope to boost this car sometime next year, most likely will go with an f1 but considering twins also.
On a side note, the camaro that this motor is in will be for sale as a rolling chassis. It's a 2000 ss silver 105k very nice shape. Has a Wolfe 5 point, line lock, some suspension upgrades, drive shaft loop, rear has axle shafts, Eaton locker, etc. And more that I'm forgetting at the moment If interested pm me
On a side note, the camaro that this motor is in will be for sale as a rolling chassis. It's a 2000 ss silver 105k very nice shape. Has a Wolfe 5 point, line lock, some suspension upgrades, drive shaft loop, rear has axle shafts, Eaton locker, etc. And more that I'm forgetting at the moment If interested pm me
Last edited by Evanniger; May 1, 2016 at 10:10 PM.