382 vs. 408
02-08-2006, 12:48 AM
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382 vs. 408 Would I be better off going with a stroker crank on my stock block and reusing my Stage II heads, or just getting a 408 long-block. Is the 408 worth the extra 90lbs of iron block? Can you get around 480rwhp with a decent 382? I know the 408 would be better for nitrous, but would the 382 be safe on a 150shot? Thanks in advance for any input!
02-08-2006, 06:35 AM
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382 can easily get over 480rwhp...and can handle a 150 shot. It depends on your heads..if they arent good LS1/LS6 then no...AFR or ETPs hell yes.
Why not a 402 LS2 long block? No weight gain and even more power....
Why not a 402 LS2 long block? No weight gain and even more power....
02-08-2006, 08:36 AM
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Have all the issues with the 402s been resloved? Knock sensors and such? I was thinking that the cheapest route would be to just go with a stroker crank and keep my heads and stuff...
02-08-2006, 08:39 AM
#4
I would imagine the stock block with 3.900" clean up bore and a 4" crank with forged rods and pistons would take almost anything you could throw at it. Maybe send your current heads off to be freshened up with the 382-383 motor in mind. Should accept a 150-200 N2O shot with no problem. Now, everything after the flywheel is a different story 
.
. 
02-08-2006, 10:43 AM
#6
I have the very same dilema.
My 347 is torn down and I was about to order the 382 rotating assy. was offered a really good deal on a callies crank and rods. My Problem is finding a shelf piston in the 9.0-9.5 range (procharger) with a 4.0 stroke.....not available. that pushes me into a custom piston and price goes up seveal hundred dollars.
After much research I have determined its actually within a couple hundred bucks of having a 408 built vs me building my 382. most of the difference lies in the crankshaft choice. If I build I was going with the callies due to much better quality control and fewer issues for the diy guy. the Eagle while strong has had issues which could lead to more machine work blah blah blah.......
Call some of the sponsors here, I think you may be surprised at some of the price quotes you will get.
My 347 is torn down and I was about to order the 382 rotating assy. was offered a really good deal on a callies crank and rods. My Problem is finding a shelf piston in the 9.0-9.5 range (procharger) with a 4.0 stroke.....not available. that pushes me into a custom piston and price goes up seveal hundred dollars.
After much research I have determined its actually within a couple hundred bucks of having a 408 built vs me building my 382. most of the difference lies in the crankshaft choice. If I build I was going with the callies due to much better quality control and fewer issues for the diy guy. the Eagle while strong has had issues which could lead to more machine work blah blah blah.......
Call some of the sponsors here, I think you may be surprised at some of the price quotes you will get.
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02-08-2006, 12:27 PM
#8
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I'm going to go with a 383 myself by this summer.
Reason is, I can keep my heads and all periferals are just plug in.
I'll be getting a Shafiroff Deluxe shortblock (with cam degreed, oil pump, plugs and covers, seals fully installed)
480 rwhp should'nt be too hard with proper cam and SCR.
Reason is, I can keep my heads and all periferals are just plug in.
I'll be getting a Shafiroff Deluxe shortblock (with cam degreed, oil pump, plugs and covers, seals fully installed)
480 rwhp should'nt be too hard with proper cam and SCR.
02-08-2006, 12:34 PM
#9
Originally Posted by ShevrolayZ28
Surely the difference from iron to aluminum is a chief concern with weight and strength, but how about rod ratios? Can anyone comment on that aspect of the various LS strokers? I hope I'm a good ways off from getting a stroker but I am curious.
List of rod ratios: (stock LS1 is 1.6828.)
http://users.erols.com/srweiss/tablersn.htm
An explanation as to what is considered a good rod ratio:
"The consensus amongst engine manufacturers is that a ratio of 1.50" is the lowest acceptable rod ratio for a street motor. Realistically, rod ratios between 1.65" - 1.80" are ideal."
More here:
http://www.fordmuscle.com/archives/2...r/index2.shtml
02-08-2006, 12:41 PM
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The short blocks may end up being the same, but wouldn't I have to get diferent heads for a 408? I could sell mine, I suppose, but I don't think I'd come near recoupind the cost of Stage III heads for a 408...
02-08-2006, 10:22 PM
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I have a set of older 5.7 Stage II heads. They've given me some really good numbers for what they are, but I don't know if they would be good for a 408... Please keep the input coming!
02-08-2006, 10:30 PM
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Originally Posted by b727pic
...After much research I have determined its actually within a couple hundred bucks of having a 408 built vs me building my 382...
02-09-2006, 12:27 AM
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The short-block may be within a few hundred bucks, but then there is the issue of the heads. Maybe I would be better off selling my current engine outright and going from there...
02-09-2006, 12:32 AM
#15
Originally Posted by Benjamin Russick
The short-block may be within a few hundred bucks, but then there is the issue of the heads. Maybe I would be better off selling my current engine outright and going from there...
So for me its purely a matter of the short block pricing
02-09-2006, 12:42 AM
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You can find some pretty good shortblock specials from the sponser's. I am very pleased with my 383 by the same token my buddy likes his 408..I like the fact that I pull him slightly in fourth gear!
02-09-2006, 10:22 AM
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Well, I've got 30lb SVOs and a big in-line pump already. I could live with the LS6/ported TB until I could swing a 90/90 combo. Shouldn't the valvetrain be included in a "long block"?
I make a pretty decent amount of power now, but the thought of some more torque N/A is very appealing. That's what prompted the "Hey! I could stuff a stroker crank in there!" thought.
I make a pretty decent amount of power now, but the thought of some more torque N/A is very appealing. That's what prompted the "Hey! I could stuff a stroker crank in there!" thought.
02-09-2006, 10:36 AM
#20
You could also get a new forged 346 short block too. That would be able to handle a 150 hp shot no problem and then you could reuse your current heads/cam combo or go even more radical. Thats what im going to do when i need a new engine. You can easily make 420+ rwhp on heads/cam alone on the stock CI, and then if you spray a direct port 150-200 shot you will be north of 600+ rwhp and tons of torque. If you have the money go 382-383 or 408, but if you trying to do it cheap as possible you can get a forged 346 short block for about $2800 ( I think FFHP is having a sale on them now) and still make gobs of power.
