I'd love to hear responses- I have in the works a 408 build.. It's going to be spring before it's planted, but I've some items laying around I thought I'd play with... Help me out here if you don't mind:

the engine is basically a stock 5.9L Magnum.. I've got an airgap I can install now (or just forgo the MPFI 4bbl intake and the plant it on the 408 and wait till then), and I have a line on a 206x cam.. If I DO install the airgap on the current (basically) stock engine, I'm thinking on putting that cam in.. It would be w/new lifters and springs, but on stock heads.. Is it worth it? (btw- I also have 1.7rr's on those heads).. I was hoping to sell the engine when I drop the 408 in, but it's not like I'm going to get a lot for it (the dang thing has 150k on it)- so, I'm figuring 'why not push it'?..

I'm asking, is there a reason for me NOT to? The lift will be close- not exactly dangerous, but close.. Is the airgap and the cam going to change my mind about the 408 and leave me grinning?

There is always the option of putting 1.6rr's or stock 1.6's back on, but clearance will be addressed before I pull the trigger.. The question of stressing out a high mileage stock 5.9L is the question I have.. It will cost me time and very little $$ to do it, that is all really.. I don't want to blow the engine into parts and pieces, as I'd still like to sell it when I'm done- THAT is the question.. Will it take it?

Your thoughts would be appreciated..

 

im in the same boat as you, however; hoping to get my 408 in a little sooner youll see some gains out of the 360, but w/o supporting mods (i.e. ported 1.92 or 2.02 heads, injectors,TB) you wont see nearly the gains that you'll see with the 408, and you will never achieve the torque.

i personally wouldnt reuse a roller cam. id just leave the current setup as is, in an attempt to keep 'er runnin till you can get the beast in there

 

what alls going into your 408?

 

I found some dudes within a couple hours of me who will build a long block for me, using top shelf products and at a silly low price of $1900... I have a laundry list of camshafts to choose from, and can choose one of three sets of heads.. I'm likely going to upgrade the heads (simply having them ported and gasket matched, intake and headers), and likely the iron's w/2.02 and 1.68..

I'm CORNFUSED and dazed by the amount of info out there concerning some other things.. I currently have a FM 52mm TB which I intended on using w/ the 408, but I've discovered something else that may change that.. I was going to use an air-gap on it, but that may change too.. Have you ever seen the 4bbl MPFI intakes and 4bbl TB's? I'm asking some questions of those guys about that now.. 1000cfm flow.. that's pretty breathy don't ya think? I'm curious enough to slow down and re-think the entire process because of it..

The 206x for my current rig (maybe) is a fresh grind.. I'm thinking about putting the air-gap on it and if I go that far, I'm thinking maybe four more hours to put that cam in.. I have an SCT, and I'll get hemifever to hook me up with a tune IF i proceed.. I'm wondering if this is lunacy- putting a new aggressive cam in a mostly stock engine, using stock heads w/ 1.7rr's (currently, I could always put the 1.6r's back on if clearance is an issue), new springs and new pushers..

I'm looking for low to mid range like you are.. I'm leaning toward the 2.02's and big gulp intake, because it pairs up with the 4.56:1's in the greater scheme- I settle at 2150-2200rpm's @ 70mph cruising.. That is home for the airgap and within range of the 2.02's to lay some power down if I stomp it.. With a load behind me and o/d off, I'll be around 3500rpm- and right in the sweet spot for that set up (on paper)..

You'll never catch me racing, and only mudding when I've done something stupid (and trying to escape).. I'm thinking the cubes of the 408 will lower the range some too and provide ample grunt down low for what I need..

how crazy is this figuring do you think?

 

mmmmm.....did somenody say 408 ..... such a naughty word i like it

 

Run the cam OR the rockers in the 360. I don't think you can get away with both, without making some other changes...... Does the cam have recommendations for new valve springs? If it does, might just sit on that for a while..... I don't think that is going to be mean enough for the 408 though..... might consider selling it as a "new part" while it still is. Put the money toward a nice cam for that 408.

The 1000 CFM throttle body is over kill. It will stifle low end performance. Even factoring 100% volumetric efficiency (which never happens outside forced induction applications...) you aren't even pulling 600 CFM at 5000 RPM...... Not sure what the stockers flow.... might be something to ask the good folks at fastman. (if they don't already have the information posted somewhere....)