mrrat1 Posted March 22, 2012 Report Share Posted March 22, 2012 Has anyone built one here? What kit did you use, ect. Thinking of getting the ls-7 heads from GM. Advice, pros & cons welcome.......thanks in advance!!!! Doing a trick hood for mine with functional cowl induction if it works out at the bodyshop.....Dave Quote Link to comment Share on other sites More sharing options...
The_aSSet Posted March 22, 2012 Report Share Posted March 22, 2012 U trying to get those cubes out of a 6.0? If you wanna do that it'll have to be stroked and bored to 427, you can just stroke to a 408 i'm pretty sure, someone will chime in soon. Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted March 23, 2012 Report Share Posted March 23, 2012 (edited) define what 427? from what i know, 2bseen had a 427 c5r motor, his truck is the current record holder for NA times http://www.silveradoss.com/forums/topic/25872-started-my-new-motor-tonight/page__p__309053__fromsearch__1#entry309053 gear m up had a 427 c5r block http://www.silveradoss.com/forums/topic/7875-427c5r-build-update/page__hl__build ss muscle truck has a 427 lq9. 4.060 bore with a 4.125 stroke subersub had a 427 LSX in his suburban http://www.silveradoss.com/forums/topic/44275-lsx-427-l92ls3-mp122hh-front-inlet-truck-setup/ supersub also has a 454 lsx http://www.silveradoss.com/forums/topic/73547-truly-pushing-it-454-lsx-tvs-2300/page__p__814918__fromsearch__1#entry814918 Adam has a 454 lsx http://www.silveradoss.com/forums/topic/63037-custom-2003-silverado-ss-for-sale/page__p__717091__fromsearch__1#entry717091 BlownFogger540 has a 427 lsx with ls7 heads http://www.silveradoss.com/forums/topic/48699-lsx-ls7-blown-project-update/ I don't know if anyone is runing a ls7 427 block or not a 408 is a 4.0 stroke with a 4.030 bore Stock lq9 is a 4.0 bore with a 3.622 stroke for ref. Edited March 23, 2012 by shadowsniper3006 (see edit history) Quote Link to comment Share on other sites More sharing options...
mrrat1 Posted March 23, 2012 Author Report Share Posted March 23, 2012 Thanks much for the links!! I definetly want to go with a cast iron block. Getting wrist pin noise pretty bad last couple winters, so getting ready for the eventual replacement. Quote Link to comment Share on other sites More sharing options...
Cramer Posted March 24, 2012 Report Share Posted March 24, 2012 In short they are telling you that you can't get a 427 out of a stock 6.0 block. A LSX block, C5R, and LS7 are capable of it. Although the LSX block is iron, and the other two are very expensive in their own. Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted March 24, 2012 Report Share Posted March 24, 2012 ss muscle truck has a 427 lq9. 4.060 bore with a 4.125 stroke . In short they are telling you that you can't get a 427 out of a stock 6.0 block. although you can argue that it is not a good idea, and in most cases be right, it can be done. grumpy has one in his truck( just kidding Joe) Quote Link to comment Share on other sites More sharing options...
slowfive0 Posted March 24, 2012 Report Share Posted March 24, 2012 (edited) I'm very interested in this topic as well. I didn't see any times of the above combos???? What's the fastest someone on this board has gone with an SS with big motor na? I've been doing a lot of research and basically in most cases you don't want to go over 4.0 stroke with standard deck blocks. In some cases, it is ok to go a bit longer stroke if the block has longer sleeves (LS7, C5R, resleeved block from ERL Performance, etc). The only other time it is recommended that you can go with a longer stroke is with a tall deck block. GMPP makes a tall deck version of the LSX, so does RHS and World Products. If you go that route it gets more expensive because of the added height of the engine. It will usually require custom headers among other things. Basically, the longer strokes can cause the piston to come out of the bottom of the block too far causing piston instability. There is ton of side loading with those longer strokes/standard sleeves and you will usually end up with more wear and oil consumption hence everyone's recommendation for 4.0 max stroke. Another problem with the big engines is they need a lot of head to avoid choking them up. Intake/tb can become an issue in some of those cases too. Overall, I think there is a great place for these larger engines when done right. I'm very interested in doing one and look forward to your results/findings. NOTE: I found a ton of good info on the different corvette forums fwiw as those guys have big wallets! Edited March 24, 2012 by slowfive0 (see edit history) Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted March 24, 2012 Report Share Posted March 24, 2012 (edited) define what 427? from what i know, 2bseen had a 427 c5r motor, his truck is the current record holder 12.14 Then mine 12.41 Then kevins 408, but I'm not sure on his et Sent from my SAMSUNG-SGH-I897 using Tapatalk Edited March 24, 2012 by shadowsniper3006 (see edit history) Quote Link to comment Share on other sites More sharing options...
slowfive0 Posted March 24, 2012 Report Share Posted March 24, 2012 Nice. Any other details about each combo? Specifically Torque converter stall? Didn't Krambo go mid 11's on motor (408)? I think a tall deck lsx with some really good heads like MAST or WCCH Pro heads would really rock it out!!!! Maybe something with a 4.125 bore and stroke in the range of 4.1 - 4.250. IIRC, that would be around 44X to 45X.... 12.14 Then mine 12.41 Then kevins 408, but I'm not sure on his et Sent from my SAMSUNG-SGH-I897 using Tapatalk Quote Link to comment Share on other sites More sharing options...
zippy Posted March 25, 2012 Report Share Posted March 25, 2012 If you want to do a 427 the best way to go is an LSx block with 4.125 bore and 4.00 stroke just like the stock LS7's come. I would use a 6.125 rod though. When you build it keep in mind that it is still just an engine and nothing more and doesn't need anything fancy. Very often someone looks into building a bigger inch motor and buy parts as if they were going to make 1500 hp with it. Don't spend big money where you aren't going to gain anything by spending the extra money and do so where it really counts. Meaning don't spend $2000 on a crank when a $1000 or less crank will more than do the same job and so on with the rods, pistons, etc, etc. Buy an LSx block, some Mahle pistons, decent crankshaft, decent rods, GM gaskets, etc, etc. When it comes to the crank and rods you won't need anything special. Simple Callies Compstar, Pep, Manley, Scat, etc will be fine. It seems that many are thrown when they think of building 408's, 416's, and 427's. My recomendations... LSx block Callies Compstar crank Callies Compstar rods Melling 10296 oil pump GM stock timing chain and gear set with chain damper (otherwise consider a 25% underdrive pulley) GM 4" stroke windage tray GM stock truck oil pan GM stock truck balancer with broached keyway LS7 heads LS7 rocker arms with Harlen Sharp roller upgrade GM LS7 gaskets or Cometic matched to correct bore size (if you use Cometic you must have the block surfaced correct for the gaskets) LSx Fast intake Nick Williams 102mm throttle body Pick a cam that seriously matches what you want to do with it. Don't just buy a big cam because it is a big motor. A well built 427 with a mild cam can make it into the 11's n/a without too much work. The key is going to be in the cylinder head. Using an LS7 head will solve that. For example GM has a new CNC ported LS7 head you can buy that flows 397cfm out of the box. With a head that flows that much it allows you to be reasonable on the camshaft size making the power with the big flow from the heads and intake rather than having to keep the valve open alot longer. The other option would be to use Trick Flow 245's which would allow you to use a Fast LSxRT intake with 102mm throttle body and the point being no changes to the accessory drive system due to the truck intake. I would also recomend a 1 7/8" or 2" primary header if possible. I've been waiting for someone to build another 427 big bore SSS and I expect we'll see one soon enough. Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted March 25, 2012 Report Share Posted March 25, 2012 (edited) Nice. Any other details about each combo? Specifically Torque converter stall? Didn't Krambo go mid 11's on motor (408)? I think a tall deck lsx with some really good heads like MAST or WCCH Pro heads would really rock it out!!!! Maybe something with a 4.125 bore and stroke in the range of 4.1 - 4.250. IIRC, that would be around 44X to 45X.... i don't know much about 2bseen's truck, you'd have to search his name and read everything you can. Not a lot of members are left on here that could remember his build, Zippy and Kevin come to mind. I have to leave it up to Kevin to post his time, I'm not even sure what his "best"(the quotes are just for you Kevin ) run on the motor was, but i know enough to say it wasn't in the 11's. He ran 11's on his 6L SC'd motor(he held the record for a long time as well with that set up ). As for his motor, he's build thread is VERY complete and i think we all have read it, as far as i know his best NA time was set with a 4500 stall. If you want to know more about Joes lq9 427 i can get into that as well, or let the man speak for himself. As far as tall deck motors go, i was going to go that route as well. After talking to Zippy and Ray about it i changed my mind. One of the issues was going to be the headers. All the headers are made for the standard deck on the lq9,lsx block and barely clear the frame rails as it is, the tall deck would create major problems with the headers fit or major cost in one off custom sets. Zippy/Ray made some other points but i can't remember them to save my soul. Edited March 25, 2012 by shadowsniper3006 (see edit history) Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted March 25, 2012 Report Share Posted March 25, 2012 (edited) When you build it keep in mind that it is still just an engine and nothing more and doesn't need anything fancy. Very often someone looks into building a bigger inch motor and buy parts as if they were going to make 1500 hp with it. I think that statement is ment to be a lesson for me..... zippy to me Edited March 25, 2012 by shadowsniper3006 (see edit history) Quote Link to comment Share on other sites More sharing options...
zippy Posted March 25, 2012 Report Share Posted March 25, 2012 I think that statement is ment to be a lesson for me..... zippy to me Not directly. I guess I'd just put you in the list with many others. There will be someone from this site that we know building a 427 or 440 soon enough which will give a great example for how to build a daily usable big power 427. Quote Link to comment Share on other sites More sharing options...
slowfive0 Posted March 25, 2012 Report Share Posted March 25, 2012 Great post Zippy! I agree wholeheartedly! Nice to have the best of the best, but not many have that kind of budget these days. Some questions about your list: 1. What is "with chain damper (otherwise consider a 25% underdrive pulley)" 2. I'm assuming we can space our stock windage tray down with head bolt washers, but you're suggesting a factory one from the LS7 that was already designed for that stroke from the factory? 3. What is a "broached" stock balancer? Is that a pinned balancer or a balancer machined for a traditional key? 4. Did you mean LS7 head gaskets or LS9 head gaskets? I'm assuming LS9.... 5. Many people/shops I've spoken to like the TFS and some say they suck. What gives? I like the idea of running those, but I am open to the LS7 design. I want whatever will work the best. 6. What are the big differences between the traditional fast intake and the truck version. I know about the accessories. Is that it? Does the truck intake have a lower powerband? More lowend/midrange torque or???? Seems like it would be the better choice for our heavy trucks as long as it breathes upstairs.... 7. Header wise, I'm assuming 1 7/8" would be the way to go for applications south of 1000hp.....Or 1 7/8 stepped to 2" if money allows... If you want to do a 427 the best way to go is an LSx block with 4.125 bore and 4.00 stroke just like the stock LS7's come. I would use a 6.125 rod though. When you build it keep in mind that it is still just an engine and nothing more and doesn't need anything fancy. Very often someone looks into building a bigger inch motor and buy parts as if they were going to make 1500 hp with it. Don't spend big money where you aren't going to gain anything by spending the extra money and do so where it really counts. Meaning don't spend $2000 on a crank when a $1000 or less crank will more than do the same job and so on with the rods, pistons, etc, etc. Buy an LSx block, some Mahle pistons, decent crankshaft, decent rods, GM gaskets, etc, etc. When it comes to the crank and rods you won't need anything special. Simple Callies Compstar, Pep, Manley, Scat, etc will be fine. It seems that many are thrown when they think of building 408's, 416's, and 427's. My recomendations... LSx block Callies Compstar crank Callies Compstar rods Melling 10296 oil pump GM stock timing chain and gear set with chain damper (otherwise consider a 25% underdrive pulley) GM 4" stroke windage tray GM stock truck oil pan GM stock truck balancer with broached keyway LS7 heads LS7 rocker arms with Harlen Sharp roller upgrade GM LS7 gaskets or Cometic matched to correct bore size (if you use Cometic you must have the block surfaced correct for the gaskets) LSx Fast intake Nick Williams 102mm throttle body Pick a cam that seriously matches what you want to do with it. Don't just buy a big cam because it is a big motor. A well built 427 with a mild cam can make it into the 11's n/a without too much work. The key is going to be in the cylinder head. Using an LS7 head will solve that. For example GM has a new CNC ported LS7 head you can buy that flows 397cfm out of the box. With a head that flows that much it allows you to be reasonable on the camshaft size making the power with the big flow from the heads and intake rather than having to keep the valve open alot longer. The other option would be to use Trick Flow 245's which would allow you to use a Fast LSxRT intake with 102mm throttle body and the point being no changes to the accessory drive system due to the truck intake. I would also recomend a 1 7/8" or 2" primary header if possible. I've been waiting for someone to build another 427 big bore SSS and I expect we'll see one soon enough. Maybe I read it wrong but I thought Kevin (Krambo right) went a little better then his best radix times on motor only???? I'm pretty sure I read that, then went 10's on spray. Are we talking about the same Kevin? Love to know more about Joes 427 build I think on the trucks, the major obstacle with the tall deck motor is the headers. Some custom headers aren't that bad if you take into account how much a really good off the shelf header costs in stainless steel or a high quality coating. I would consider it as long as the benefits of the tall deck were worth it. Seems like there are some really good benefits that not many explore. I wish I could find more tall deck combos that people have done......I don't have the budget to "experiment" lol! Good luck with your project! i don't know much about 2bseen's truck, you'd have to search his name and read everything you can. Not a lot of members are left on here that could remember his build, Zippy and Kevin come to mind. I have to leave it up to Kevin to post his time, I'm not even sure what his "best"(the quotes are just for you Kevin ) run on the motor was, but i know enough to say it wasn't in the 11's. He ran 11's on his 6L SC'd motor(he held the record for a long time as well with that set up ). As for his motor, he's build thread is VERY complete and i think we all have read it, as far as i know his best NA time was set with a 4500 stall. If you want to know more about Joes lq9 427 i can get into that as well, or let the man speak for himself. As far as tall deck motors go, i was going to go that route as well. After talking to Zippy and Ray about it i changed my mind. One of the issues was going to be the headers. All the headers are made for the standard deck on the lq9,lsx block and barely clear the frame rails as it is, the tall deck would create major problems with the headers fit or major cost in one off custom sets. Zippy/Ray made some other points but i can't remember them to save my soul. Details? Not directly. I guess I'd just put you in the list with many others. There will be someone from this site that we know building a 427 or 440 soon enough which will give a great example for how to build a daily usable big power 427. 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slowfive0 Posted March 26, 2012 Report Share Posted March 26, 2012 One other interesting thread I found. Food for thought. I called these guys up and they claimed that on some maggie combinations up close to 1000 hp, the 390 made 80-90hp more then the 408. The only difference being the 3.8 stroke vs the 4.0 stroke........The shop seems to be highly respected and not a fly by night operation. I can see some benefits of the slightly shorter stroke vs the cylinder bore length but I'm unsure of 80-90hp benefit.........Doesn't seem possible, maybe 20-30 hp. http://ls1tech.com/forums/forced-induction/1359652-aes-390ci-now-callies-dragonslayer-crankshaft.html Quote Link to comment Share on other sites More sharing options...
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